Conducting Polymers and Their Applications to Biosensors ...

1942 IEEE SENSORS JOURNAL, VOL. 9, NO. 12, DECEMBER 2009 

Conducting Polymers and Their Applications 

to Biosensors: Emphasizing on 

Foodborne Pathogen Detection 

Khalil Arshak, Vijayalakshmi Velusamy, Olga Korostynska, Kamila Oliwa-Stasiak, and Catherine Adley 

Abstract—Detection of microbial pathogens in food is the solution 

to the prevention and recognition of problems related to 

health and safety. New biomolecular approaches for foodborne 

pathogen detection are being developed to improve the biosensor 

characteristics such as sensitivity and selectivity, also which is 

rapid, reliable, cost-effective, and suitable for in situ analysis. 

Recently, conducting polymers have drawn attention in the development 

of biosensors. The electrically conducting polymers 

have numerous features, which allow them to act as excellent 

materials for immobilization of biomolecules. Also, their unique 

properties make them appealing alternatives for specific materials 

currently employed for the fabrication of biosensors. Therefore, 

this paper presents a comprehensive literature review detailing 

the salient features of conducting polymers and their application 

to biosensors with an emphasis on foodborne pathogen detection. 

Index Terms—Biosensors, conducting polymers, foodborne 

pathogen detection, identification, immobilization, quantification, 

transducer. 

I. INTRODUCTION 

ALTHOUGH food safety has dramatically improved 

overall, progress is uneven and foodborne outbreaks 

from microbial contamination, chemicals and toxins are 

common in many countries [1]. Therefore, the role of pathogen 

detection technology is vital, which is the key to the prevention 

and identification of problems related to health and safety. But 

still, a detection technique which is reliable, rapid, accurate, 

simple, sensitive, selective, cost effective and also suitable for 

in situ analysis is yet to be developed. 

Conducting polymers have unique properties which make 

them appealing alternatives for specific materials currently 

employed for the fabrication of biosensors. Since, the literature 

related to application of conducting polymers to biosensors is 

vast; this paper reports mainly on the detection, identification 

and quantification of foodborne pathogens. 

Manuscript received October 21, 2008; revised April 28, 2009; accepted August 

31, 2009. Current version published November 04, 2009. The associate editor 

coordinating the review of this paper and approving it for publication was 

Prof. Massood Atashbar. This work was supported in part by the Science Foundation 

Ireland (SFI) Research Frontiers Program under 07RPF-ENEF500. 

K. Arshak, V. Velusamy, and O. Korostynska are with the Department of 

Electronic and Computer Engineering, University of Limerick, Limerick, Ireland 

(e-mail: khalil.arshak@ul.ie; viji.subha@ul.ie; olga.korostynska@ul.ie). 

K. Oliwa-Stasiak and C. Adley are with the Microbiology Laboratory, Department 

of Chemical and Environmental Sciences, University of Limerick, 

Limerick, Ireland (e-mail: kamila.oliwa@ul.ie; Catherine.adley@ul.ie). 

Digital Object Identifier 10.1109/JSEN.2009.2032052 

1530-437X/$26.00 © 2009 IEEE 

Fig. 1. Polyacetylene chain. 

A. What Makes Polymers Conductive? 

Polymers (plastics) are known to have good insulating properties 

and are among the most used materials in the modern 

world. However, it has been discovered that there are some polymers 

which have conducting properties. Conducting polymers 

are polymer materials with metallic and semiconductor characteristics, 

a combination of properties not exhibited by any other 

known material. A key property of a conductive polymer is the 

presence of conjugated double bonds along the backbone of the 

polymer. In conjugation, the bonds between the carbon atoms 

are alternately single and double. For example, structure of polyacetylene 

is shown in Fig. 1. 

Since the electrons in a conjugated system are only loosely 

bound, electron flow may be possible. Every bond contains a localized 

“sigma” bond which forms a strong chemical bond. 

In addition, every double bond also contains a less strongly localized 

“pi” bond which is weaker. These enable the electrons 

to be delocalized over the whole system and so be shared 

by many atoms. This means that the delocalized electrons may 

move around the whole system. However, conjugation is not 

enough to make the polymer material conductive. In addition, 

the polymer material needs to be doped for electron flow to 

occur. Doping is either the addition of electrons (reduction reaction) 

or the removal of electrons (oxidation reaction) from 

the polymer. An oxidation doping (removal of electrons) can 

be done using iodine. The iodine attracts an electron from the 

polymer from one of the bonds. Once doping has occurred, the 

electrons in the -bonds are able to “jump” around the polymer 

chain. As the electrons are moving along the molecule, electric 

current occurs. For better conductivity the molecules must be 

well ordered and closely packed to limit the distance “jumped” 

by the electrons. The conductivity of conducting polymers can 

be tuned by chemical manipulation of the polymer backbone, 

by the nature of the dopant, by the degree of doping, and by 

blending with other polymers [2]. 

B. Discovery and Application of Conducting Polymers 

The Nobel Prize in Chemistry for 2000 was awarded to three 

scientists—Alan J. Heeger, Alan G. MacDiarmid, and Hideki 

Authorized licensed use limited to: University of Limerick. Downloaded on November 3, 2009 at 07:08 from IEEE Xplore. Restrictions apply.

ARSHAK et al.: CONDUCTING POLYMERS AND THEIR APPLICATIONS TO BIOSENSORS 1943 

Shirakawa for the discovery and development of conductive 

polymers. They discovered that a polymer, namely polyacetylene, 

can be made conductive almost like a metal. Polyacetylene 

was already known as a black powder when in 1974 Shirakawa 

and co-workers prepared a silvery film from acetylene, using a 

Ziegler-Natta catalyst [3]. Though it appeared to be metallic, 

it was not a conductor. Later in 1977, Shirakawa, MacDiarmid 

and Heeger, and co-workers discovered that when silvery films 

of the semiconducting polymer, trans “polyacetylene,” (CH)x 

are exposed to chlorine, bromine, or iodine vapor, uptake of 

halogen occurs, and the conductivity increases noticeably (over 

in the case of iodine). Also it has been reported that depending 

on the extent of halogenation, silvery or silvery-black 

films, high conductivity at room temperature can be obtained 

[4]. Treatment with halogen was called “doping” by analogous 

to doping of semiconductors. The doped form of polyacetylene 

had a conductivity of Siemens per meter, which was higher 

than that of any previously known polymer. 

Their work opened up polymer electronics, expected to be the 

electronics technology of the near future and predominantly in 

molecular electronics. Conducting polymers have potential applications 

at all levels of microelectronics like electrostatic discharge 

(ESD), electromagnetic interference (EMI) shielding, interconnection 

technologies, corrosion protection of metals, and 

in devices like diodes, transistors, sensors, biosensors, and actuators. 

In addition, polymeric materials are lightweight, flexible, 

and can be easily processed which makes them suitable for 

micro and nanoscale molecular electronic devices. Also, they 

find application in the detection of single molecule, thus creating 

future opportunities for high sensitivity sensors and biosensors. 

II. TYPES OF CONDUCTING POLYMERS 

Only emeraldine polymer exhibits conductivity. If emeraldine-base 

polymer is treated with acidic solution (either organic 

or inorganic protonic acids) with pH lower than 4, it is converted 

to emeraldine salt form which is the conducting form of the 

emeraldine polymer. If the polymer is treated with a solution 

with pH greater than 4, the polymer becomes insulator [5]. 

Common conducting polymers are poly(acetylene)s, poly 

(pyrrole)s, poly(thiophene)s, poly(terthiophene)s, poly(aniline)s, 

poly(fluorine)s, poly(3-alkylthiophene)s, polytetrathiafulvalenes, 

polynapthalenes, poly( -phenylene sulfide), 

poly( -phenylenevinylene)s, poly(3,4-ethylenedioxythiophene), 

polyparaphenylene, polyazulene, polyparaphenylene 

sulfide, polycarbazole, and polydiaminonaphthalene [6]. 

Among the various conducting polymers polyaniline, polythiophene, 

and polypyrrole, are biocompatible and hence, cause 

minimal and reversible disturbance to the working environment 

and protect electrodes from fouling [7]. However, only 

polyaniline, polypyrrole are most extensive used in biosensors 

for foodborne pathogen detection. Recently, conducting 

Fig. 2. Structure of polyaniline. 

polymer nanocomposites which have enhanced properties has 

been developed to overcome the inherent limitations of pure 

conducting polymers [8]. 

The use of conducting polymer nanocomposites/nanoparticles 

could greatly improve diffusion since they have much 

greater exposed surface area and as a result of this the basic 

characteristics of a biosensor like low detection limit get 

enhanced. The oriented microstructure and the high surface 

area also facilitate high biomolecule loading and hence highly 

sensitive detection is possible. Moreover, the relative stability is 

increased due to efficient bonding of biomolecule on the transducer 

surface which improves reproducibility. These materials 

are especially important because of their bridging role between 

the world of conducting polymers and that of nanoparticles [9]. 

The promising features of conducting polymer nanocomposites 

are also discussed in literature [10]–[15]. Pal and Alocilja [14] 

has developed electrically active polyaniline coated magnetic 

(EAPM) nanoparticle-based biosensor for the detection of 

Bacillus anthracis endospores in contaminated food samples. 

The 100 nm-diameter EAPM nanoparticles are synthesized 

from aniline monomer (made electrically active by acid doping) 

coating the surface of gamma iron oxide cores. Experimental 

results indicate that the biosensor is able to detect B. anthracis 

spores at concentrations as low as spores/ml from the 

samples with a total detection time of 16 min. Ma et al. [16] used 

a nanocomposite of poly(anilineboronic acid), a self-doped 

polyaniline, with ss-DNA-wrapped single-walled carbon nanotubes 

(ss-DNA/SWNTs) to fabricate on a gold electrode by in 

situ electrochemical polymerization of 3-aminophenylboronic 

acid monomers in the presence of ssDNA/SWNTs. The paper 

reported that the sensitivity increased four orders of magnitude 

when nanocomposite was used to detect nanomolar concentrations 

of dopamine compared to the detection at an electrode 

modified with only poly(anilineboronic acid). 

A. Polyaniline 

Among the other organic conjugated polymers, polyaniline 

received considerable attention in recent years due to its high 

conductivity in the doped state (up to 1 S/cm), the polymerization 

reaction can be easily controlled to give high yields, 

the monomer is inexpensive, its excellent environmental and 

thermal stability as well as the electrochemical stability [5], 

[17]. The structure of polyaniline is shown in Fig. 2. 

The emeraldine salt form of polyaniline can be easily obtained 

by HCl doping which imparts good environmental and 

thermal stability, while enhancing relatively high conductivity 

[17]. The responsive nature of polyaniline is highly dependent 

on processing conditions, film composition, and morphology. 

The mechanisms employed in producing polyaniline films for 

chemical/biological sensing determine the level of electrical 

conductivity, overall structure, and stability [18]. Langer and 



Fig. 3. Structure of polypyrrole. 

Langer developed a nanobiodetector to observe the specific 

changes in the electrical conductivity of a polyaniline micro and 

nanofibril network in the presence of micro-organisms [19]. It 

has been observed that the electrical conductivity of polyaniline 

micro and nanofibrils is strongly dependent on the temperature 

and the chemical environment. The paper reported that the 

electrical response depends on the number of cells deposited on 

the polyaniline nanonetwork, and is specific to different kinds 

of micro-organisms with very low detection limit. 

Among other conducting polymers, polyaniline is often used 

as an immobilizing substrate for biomolecules [7] and it has 

proven particularly useful in the development of biosensors 

[20]. However, the intractability of polyaniline has limited its 

utilization in commercial biosensors, especially in its pure, inherently 

conductive form [21], [22]. Dispersion of polyaniline 

is one of the interesting ways to improve the processability of 

Polyaniline. Morrin et al. [21] developed a simple fabrication 

method for a biosensor by depositing polyaniline nanoparticles, 

where the dispersions were cast onto disposable screen-printed 

electrodes by means of drop-coating. The paper reported that 

the method was shown to be an effective biosensor format. 

Also, the signal-to-background (S/B) was comparable to the 

biosensor developed using electrodeposited nanoparticles [20]. 

B. Polypyyrole 

Polypyrrole is one of the most attractive conducting polymers 

with some special electrical properties. These properties 

originate from the fact that Polypyrrole is an intrinsically conducting 

polymer and can be synthesized to have conductivities 

up to 1000 S/cm which approaches the conductivity of metals. 

Electrical conduction in polypyrrole is the result of electron 

movement within delocalized orbitals and positive charge defects 

known as polarons [23]. In conjugated polymers other 

than polyacetylene, electrons added or removed from the delocalized 

-bonded backbone initially produce polarons (radical 

ions coupled to a spatially extended distortion of the bond 

lengths) which subsequently combine to form dianions or dications 

(spinless bipolarons), respectively [24]. In polyacetylene, 

anions and cations are produced during charge transfer. Most 

practical types of Polypyrrole have conductivities in the range of 

1–100 S/cm [9]. The structure of polypyrrole is shown in Fig. 3. 

Polypyrrole is used mostly in biosensors and immunosensors 

because of the best biocompatibility and the ease of immobilization 

of various biologically active compounds [25]. To detect 

bio-analytes at a physiological pH, biosensing materials must 

be electroactive in neutral environments, unlike polyaniline and 

polythiophene. To overcome this problem, polypyrrole is found 

to be very attractive because it can be more easily deposited 

from neutral pH aqueous solutions of pyrrolemonomers [26]. 

Fig. 4. Schematic diagram of a biosensor. 

DNA can form a strong bond with polypyrrole based on the interchanging 

of dopant DNA molecules [27] and hence it has attracted 

attention of various researchers for application of DNA 

biosensors [28]. 

Recently, Zanuy and Aleman [29] examined the ability 

of pyrrole and thiophene, which are the monomeric units of 

polypyrrole and polythiophene, respectively, to interact with 

the methylated analogues of DNA bases, 9-methyladenine 

(mA), 9-methylguanine (mG), 1-methylcytosine (mC), and 

1-methylthymine (mT) through specific hydrogen-bonding 

interactions. Results evidenced that pyrrole is a strong proton 

donor, able to form very stable complexes with mA, mG, mC, 

and mT. Moreover, the specificity of pyrrole to methylated 

nucleic acids is very remarkable. On the other hand, the sulfur 

of thiophene is a very weak proton acceptor as was revealed 

by the fact that no hydrogen-bonded complex was formed with 

mA, mC, and mT. The paper reported that the results were fully 

consistent with the high affinity of polypyrrole toward plasmid 

DNA, as well as with the ability of this polymer to form specific 

interactions with well-defined nucleotide sequences protecting 

DNA from enzymatic digestion. 

III. BIOSENSORS 

A. Introduction to Biosensors 

A biosensor is an analytical device, which converts a biological 

response into an electrical signal. It consists of two main 

components: a bioreceptor or biorecognition element, which 

recognizes the target analyte and a transducer, for converting the 

recognition event into a measurable electrical signal. A bioreceptor 

can be a tissue, microorganisms, organelles, cells, enzymes, 

antibodies, nucleic acids and biomimic and the transduction 

may be optical, electrochemical, thermometric, piezoelectric, 

magnetic and micromechanical or combinations of one 

or more of the above techniques. 

Fig. 4 shows schematic diagram of a biosensor. The bioreceptor 

recognizes the target analyte and the corresponding biological 

responses are then converted into equivalent electrical 

signals by the transducer. The amplifier in the biosensor responds 

to the small input signal from the transducer and delivers 

a large output signal that contains the essential waveform features 

of an input signal. The amplified signal is then processed 

by the signal processor where it can later be stored, displayed 

and analyzed. Biosensors have been widely applied to a variety 

of analytical problems in medicine, the environment, food, 

process industries, security, and defense. 



Fig. 5. The three generations of a biosensor. 

B. Generations of Biosensor 

Depending on the level of integration, biosensors can be 

divided into three generations, i.e., the method of attachment 

of the biorecognition element or the bioreceptor molecule to 

the base of the transducer element. The three generations of a 

biosensor are depicted in Fig. 5. 

In the first generation, the biorecognition element or the 

bioreceptor molecule is either bound to or entrapped in a membrane, 

which in turn is fixed on the surface of the transducer 

(based on Clark biosensors [30]). The mediated or second-generation 

biosensors use specific mediators between the reaction 

and the transducer to improve sensitivity. It involves the adsorption 

or covalent fixation of the biologically active component to 

the transducer surface and permits the elimination of semi-permeable 

membrane. In the case of third-generation biosensors or 

direct biosensors, it is the direct binding of the bioreceptor molecule 

to the sensor element, and thus the bioreceptor molecule 

becomes an integral part of the biosensor. So no normal product 

or mediator diffusion is directly involved in this. Conducting 

polymer-based biosensors come under this category. 

C. Classifications of Biosensor 

Biosensors can be classified by their bioreceptor or their 

transducer type. Fig. 6 shows the biosensor classifications. 

Bioreceptors: Classified into five different major categories. 

These categories include antibody/antigen, enzymes, nucleic 

acids/DNA/RNA, cellular structures/cells, and biomimetic. The 

enzymes, antibodies, and nucleic acids are the main classes of 

bioreceptors which are widely used in biosensor applications. 

Though the enzymes are one of the biorecognition elements, 

they are mostly used to function as labels than the actual 

bioreceptor. 

Transducers: The transducer plays an important role in the 

detection process of a biosensor. In case of conducting polymer- 

based biosensor, the conductive polymer acts as a transducer 

that converts the biological signal to an electrical signal. Biosensors 

can also be classified based upon the transduction methods 

they employ. Wide varieties of transduction methods have been 

developed in the past decade for the detection of foodborne 

pathogens. 

Although there are new types of transducers constantly being 

developed for use in biosensors, the transduction methods 

such as optical, electrochemical, and mass based are given 

importance here since these are the most popular and common 

methods. Each of these three main classes contains many different 

subclasses and they can be further divided into label and 

label-free (nonlabeled) methods, where, the labeled methods 

depend on the detection of a specific label (e.g., fluorescence) 

and the label-free detection is based on the direct measurement 

of a product developing during the biochemical reactions on a 

transducer surface. 

IV. SIGNIFICANCE OF CONDUCTING POLYMERS TO BIOSENSORS 

Conducting polymers have been used as a transducer in biological 

sensors due to its attractive properties and their use in 

biosensors has grown over the past decade. Some of the attractive 

features of conducting polymers for biosensor applications 

include: 

• Availability of varied range of monomer types. 

• Availability synthetic analogues of monomers. 

• Composites can be prepared combing conducting polymers 

with nonconducting polymers or with nonpolymer 

materials such carbon, carbon nanotubes, metals, etc. 

• It can be prepared both electrochemically and chemically. 

• It can be prepared in a range of soluble and insoluble forms. 

• It has unique electrical, electronic, magnetic and optical 

properties. 

• Compliance with micro and nanoscale fabrication. 

• Compatibility with diverse range of fabrication techniques 

such as electrochemical, optical, mass-based, etc. 

• Biomaterials such as enzymes, antibodies, whole cells, and 

nucleic acids can be incorporated into the polymer matrix. 

• Strong biomolecular interactions. 

• Low detection limits. 

• Enhanced sensitivity (when used as a composite material 

with nanoparticles). 

• Reversible responses at ambient temperatures. 

• Cost effectiveness. 

V. IMMOBILIZATION OF BIOMOLECULES INTO THE 

CONDUCTING POLYMER 

Conducting polymers are excellent platforms for the immobilisation 

of biomolecules at electrodes [32] since, they 

are known to provide better signal transduction, enhanced 

sensitivity, selectivity, durability, biocompatibility, direct electrochemical 

synthesis, and flexibility for the immobilization of 

biomolecules, including DNA [10]. For biosensor applications, 

immobilisation of biorecognition elements such as enzymes, 

antibodies, whole cell or the DNA on the polymeric surface 

is vital to perform selective and efficient bioanalyte detection. 

The commonly used immobilization methods are physical 

adsorption, electrochemical adsorption, covalent attachment 



and avidin-biotin. Generally, covalent immobilization is often 

preferred to physical adsorption to avoid leaching of the 

bioreceptor [33]. To immobilize the DNA onto the electrode, 

covalent immobilization and biotin-avidin immobilization 

methods appear to be the most appropriate techniques for fabrication 

of DNA hybridization electrodes [28]. This is because 

the probe DNA is held onto the transducer surface at one end 

having the backbone of the single stranded DNA free onto the 

surface giving desired flexibility and hybridization will be rapid 

with the complementary strand. 

For biosensor applications, protein entrapment is one the 

techniques used to immobilize bioreceptors on the transducer 

surface. However, this technique is not applicable for polyaniline 

because this polymer is synthesized under highly acidic 

(pH 0–2) solutions conditions [33]. Surface modification of 

polymers via molecular design is one of the most versatile 

means to modify surface properties of polymer films. For this 

reason, Crombrugghe et al. [33] demonstrated the thermal 

grafting of acrylic acid (AAc) monomers on polyaniline films 

obtained by electroless deposition. The paper reported that 

carboxylic groups can be used for covalent immobilization 

of proteins, like ICHA antigen, by means of standard coupling 

agents (carbodiimide and succinimide). Surface analysis 

showed that amount of antigen immobilized on the surface was 

higher as compared with simple physical adsorption. Therefore, 

acrylic grafting on polyaniline introduces a new access to its 

biochemical functionalization. 

VI. CONDUCTING POLYMER BASED BIOSENSOR FOR 

FOODBORNE PATHOGEN DETECTION 

A. Electrochemical Biosensor 

Electrochemical-based detection methods are another possible 

means of transduction that has been used for identification 

and quantification of foodborne pathogens. Electrochemical 

biosensors can be classified into amperometric, potentiometric, 

impedimetric and conductometric, based on the observed 

parameters such as current, potential, impedance, and conductance, 

respectively. Although the electrochemical detection has 

several advantages like low cost, ability to work with turbid 

samples, and easy miniaturization, their sensitivity and selectivity 

is slightly limited when compared to optical detection. 

Fig. 6. The biosensor classifications. 

However, electrochemical biosensors were found coupled with 

other biosensing techniques for enhanced detection. 

Also, electrochemical polymerization is an effective technique 

for the deposition of conducting polymers onto various 

substrates and following are the advantages of electrochemical 

deposition. 

i) It allows the reproducible and precise formation of a conducting 

polymer coating over surfaces whatever their size 

and geometry. 

ii) Growth of the conducting polymer can be controlled. 

iii) The polymeric films are stable in organic and aqueous 

solvents. 

Amperometric Detection: Amperometric transduction is the 

most common electrochemical detection method which has 

been used for pathogen detection and it has superior sensitivity 

than potentiometic method. In amperometric-based detection, 

the sensor potential is set at a value where the analyte produces 

current. Thus, the applied potential serves as the driving force 

for the electron transfer reaction, and the current produced is a 

direct measure of the rate of electron transfer. 

Minett et al. [34], coupled conducting polymers and the 

electron mediators for the detection of Listeria monocytogenes. 

Different signal generation techniques were investigated for 

the detection of L. monocytogenes at both bare and polymer 

(polypyrrole)-modified electrodes. The paper reported that conventional 

amperometry at an antibody-containing polypyrrole 

film electrode was found to be unsuccessful in detecting levels 

below cells/mL. More successful was the coupling of a 

covalently modified film with the use of electron mediators 

in a single device. It was found that the use of conventional 

techniques such as voltammetry was successful in detecting 

high levels of micro-organisms ( cells/mL Listeria). 

However, these techniques suffered from a lack of reproducibility 

between polymer films and an inability to detect 

small viable numbers. Improving the immobilization of the 

antibody (covalent attachment) met with little success when 

using voltammetry. Although detection was possible, detecting 

low levels of micro-organisms was beyond the capabilities 

of the technique in these experiments. The use of Toluidine 

Blue at a bare glassy carbon electrode also proved successful 

in detecting Listeria at concentrations of cells/mL. The 

method was not specific as responses were also obtained for 

other micro-organisms, such as E. coli and Salmonella. The 



coupling of mediated voltammetry with the covalent attachment 

method of immobilizing the anti-Listeria in one sensor showed 

a decrease in detection levels by one order of magnitude. It 

was found that levels as low as cells/mL of Listeria could 

be detected after incubation in the micro-organism culture for 

30 min. 

Based on amperometric method, Ghosh et al. [35] reported 

the fabrication of an electrochemical biosensor to detect fish 

freshness using conducting polypyrrole. Freshness was indicated 

by freshness index, K1 or hypoxanthine index, H which 

depends on the amount of these autodegradation of adenosine 

-triphosphate (ATP) degradation products present in fish 

meat. These degradation metabolites have been detected efficiently 

by amperometric method using three new ferrocene 

carboxylic acid (FCA) mediator incorporated conducting 

polypyrrole enzyme electrodes with immobilized xanthine 

oxidase, nucleoside phosphorylase and nucleotidase enzymes 

for quantitative measurement of hypoxanthine, inosine, and 

inosine monophosphate, respectively. This simple, fast and 

ready to use biosensor has been used to measure the H values 

of fresh water fish Catla-Catla over days of storage. Results 

showed that the fish degrades very rapidly after seven days even 

when stored at C and suggest that fish freshness can be 

monitored quantitatively with this biosensor. Velusamy et al. 

[36] developed a model DNA biosensor for the detection of 

Bacillus cereus using the electrochemical deposition technique, 

such as cyclic voltammetry (CV). Polypyrrole was used as a 

platform for immobilizing DNA (1 g) on the gold electrode 

surface, since it can be more easily deposited from neutral 

pH aqueous solutions of pyrrolemonomers. The model DNA 

biosensor generated unique CV signals between complementary 

and noncomplementary oligonucleotides. 

Potentiometric Detection: In potentiometric-based detection, 

the biorecognition process is converted into a potential signal. 

Usually, a high impedance voltmeter is used to measure the electrical 

potential difference or electromotive force (EMF) between 

two electrodes at near zero current. Since potentiometry generates 

a logarithmic concentration response, the technique allows 

the detection of extremely small concentration changes. Though 

the application of conducting polymers based on potentiometric 

detection has been reported by many researchers, no paper has 

been published yet for the detection of foodborne pathogens. 

Impedimetric Detection: The integration of impedance with 

biological recognition technology for detection of pathogens 

has led to the development of impedance biosensors that are 

finding widespread use in the recent years [37]. Impedimetric 

transduction technique has been applied to detect and/or 

quantify variety of foodborne pathogens. Electrochemical 

impedance spectroscopy (EIS) is playing an important role 

in the biosensor development. In EIS measurements, a controlled 

AC electrical stimulus of between 5–10 mV is applied 

over a range of frequencies, and this causes a current to flow 

through the biosensor, depending on different processes. EIS 

is a widely used technique for probing bioaffinity interactions 

at the surfaces of electrically conducting polymers and can be 

employed to investigate “label free” detection of analytes via 

impedimetric transduction [32]. 

Recently, Tully et al. [32] described the development of a 

direct immunosensor for the detection of a cell-surface pro- 

tein on Listeria monocytogenes. The paper reported, how a 

portion of the recombinant Internalin B (In1B) protein, the F3 

fragment, and an anti-InlB polyclonal antibody, were used to 

develop a platform for the labeless immunosensing of InlB. 

Sensors were fabricated by electropolymerisation of planar 

screen-printed carbon electrodes with polyaniline to produce a 

conductive substrate. Polyclonal anti-InlB antibody was subsequently 

incorporated onto the PANI layer using a biotin-avidin 

system for site-specific immobilisation. The sensors were then 

probed with varying concentrations of InlB antigen and the 

impedimetric response at each concentration was recorded. An 

anti-IgG antibody was immobilized at the electrode surface, as 

a control and subsequently exposed to the same concentrations 

of InlB. Upon exposure to a range of concentrations of antigen, 

complex plane impedance analyses were used to relate the differing 

redox states of the polymer layer, to the possible charge 

transfer at the surface, with respect to the related mechanisms 

between the antibody and the polymer. These effects were 

subsequently monitored to assess the impedance of the polymer 

thereby determining the amount of bound antigen at the sensor 

surface. A limit of detection of 4.1 pg/ml was achieved for 

Internalin B. 

Though EIS offers label free detection compared to amperometry 

or potentiometry, its detection limits are inferior compared 

to traditional methods. 

Conductometric Detection: Conductometric-based biosensors 

bond the relationship between conductance and a biorecognition 

technique. Most reactions involve a change in the ionic 

species concentration, which leads to a change in electrical 

conductivity or current flow. Normally, a conductometric 

biosensor consists of two metal electrodes separated by a certain 

distance and an AC voltage applied across the electrodes 

causes a current flow. During a biorecognition event, the ionic 

composition changes and the change in conductance between 

the metal electrodes are measured. 

Muhammad-Tahir and Alocilja [38] developed a biosensor 

based on an electrochemical sandwich immunoassay using 

polyaniline for detecting foodborne pathogens, such as 

Escherichia coli (E. coli) O157:H7. The paper reported 

the performance of a biosensor based on polyaniline as an 

electrochemical transducer in measuring an immune reaction. 

Their results showed that the biosensor was able detect approximately 

cfu/mL of E. coli O157:H7 in 10 min. Later 

the same group of researchers [39] described a novel biosensor 

based on polyaniline as a label for the electrochemical sandwich 

immunoassay for E. coli O157:H7 detection in fresh 

produce such as lettuce, alfalfa sprouts, and strawberries. The 

biosensor design is based upon the specific nature of labelled 

antibody-antigen binding. Results showed that the biosensor 

can detect an average of 81 CFU/ml in nine samples in 6 mins. 

Another factor adding to the potential value of the biosensor 

was its versatility. The paper suggested that by using antibodies 

with varying specificities, the biosensor can be made to detect 

many different analytes. Also, the above group of researchers, 

Alocilja and Muhammad-Tahir, developed a biosensor for 

detecting bacteria using water soluble polyaniline, where the 

fluid electrically conductive polymer bounds to the capture 

reagent that captures analyte in sample and migrates to capture 

zone where complexed analyte is captured by another capture 



reagent [40]. Results showed that the conductimetric biosensor 

device based on antibody-antigen binding has sensitivity detect 

as low as 100–101 cfu of E. coli in 2–10 min [40]. Also, it has 

been reported that the device is reliable, rapid, can easily be 

miniaturized, can be produced economically, and can be used 

for on site analysis. Recently, Pal et al. [41] developed a direct-charge 

transfer conductometric biosensor for the detection 

of Bacillus cereus in various food samples. 

The biosensor used the principle of a sandwich immunoassay, 

combined with an electron charge flow aided through conductive 

polyaniline, to generate an electronic signal. The biosensor 

was able to detect cell concentrations in the range of 35–88 

CFU/mL in the food samples with a detection time of 6 minutes. 

The biosensor was found to be specific to the target pathogen in 

pure cultures of Bacillus megaterium and generic E. coli. Also, 

it has been reported that the speed, sensitivity and ease of use, of 

this biosensor make it a promising device for rapid field-based 

diagnosis toward the protection of the food supply chain. The 

summary of electrochemical biosensors using conducting polymers 

for the detection of various foodborne pathogens are given 

in Table I. 

B. Optical-Based Biosensors 

Optical biosensors have received considerable interest for 

bacterial pathogen detection due to their sensitivity and selectivity. 

Optical biosensors are based on the measurement of 

light absorbed or emitted as a result of a biochemical reaction. 

Optical-based detection offers a large number of subclasses 

based on absorption, reflection, refraction, dispersion, infrared, 

Raman, chemiluminescence, fluorescence, and phosphorescence. 

However, all the above subclasses require a suitable 

spectrometer to record the spectrochemical properties of the 

analyte. 

The most commonly employed techniques of optical detection 

are surface plasmon resonance and fluorescence due to their 

sensitivity. Optical techniques using fiberoptics, laser, prism, 

and waveguides are also employed for pathogen detection 

[43]–[45]. Among the conducting polymers, polydiacetylenes 

(PDAs) are of particular interest in optical biosensors since 

they exhibit strong optical absorption and fluorescence emission 

[46]. Optical absorption in PDAs occurs via a -to- * 

TABLE I 

CONDUCTING POLYMERS USED FOR FOODBORNE PATHOGEN DETECTION 

absorption within the linear -conjugated polymer backbone. 

Unpolymerized films do not exhibit absorption in the visible 

region. Upon polymerization, frequently the first chromogenically 

interesting state of the PDA appears blue in color, with 

absorption maximum in the range of nm, although other 

features including a prominent vibronic side-peak are readily 

apparent. The chromogenic transitions will involve a significant 

shift in absorption from low- to high-energy bands of the visible 

spectrum, where the PDA transforms from a blue to a red color, 

with an absorption maximum in the range of nm [46]. 

Colorimetric and Fluorescence Detection: As a potential 

materials for optic biosensor, the surface properties of the 

polydiacetylene films fuctionalized with glycolipid on pure 

water are interesting and important [47]. A supramolecular 

assembly of phospholipid- polymerized diacetylene vesicles 

functionalized with glycolipid can provide a molecular recognition 

function [48]. The use of a biochromic conjugated polymer 

(BCP) sensors for pathogen detection was demonstrated by 

Song et al. [49]. Biologically active cell membrane components 

were incorporated into conjugated polymers with desirable 

optical properties. Polydiacetylenic membrane-mimicking materials 

that mimic the cell membrane and conveniently report 

the presence of pathogens with a color change were used for the 

colorimetric detection of bacterial toxins and influenza virus. 

It has been suggested that the BCP sensors are convenient for 

microfabrication and use, since their molecular recognition 

and signal transduction functionalities are resident in a single 

functional unit [49]. Su et al. [48] reported the fabrication of 

mixed phospholipid/polydiacetylene vesicles functionalized 

with glycolipid for detection of E. coli. The paper reported 

that E. coli-glycolipid binding event leads to a visible color 

change from blue to red, readily seen with the naked eye and 

quantified by absorption spectroscopy. The biosensor signal 

amplification has been gained through elevating the pH of the 

aqueous solutions and increasing the phospholipid content in 

the mixed lipid vesicles. 

Silbert et al. [50] presented a new platform for visual and 

spectroscopic detection of bacteria based on colorimetric and 

fluorescence transformations induced within lipid-polymer 

assemblies by bacterially released substances. The detection 

scheme in their study was based on the interaction 



of membrane-active compounds secreted by bacteria with 

agar-embedded nanoparticles comprising phospholipids and 

the chromatic polymer polydiacetylene (PDA). PDA undergoes 

dramatic visible blue-to-red transformations together with an 

intense fluorescence emission that are induced by molecules 

released by multiplying bacteria. The chromatic transitions was 

easily identified by the naked eye and they suggested that since 

the chromatic technology is generic and simple, eliminating the 

need for prior identification of specific bacterial recognition elements, 

this can be applied for detection of both gram-negative 

and gram-positive bacteria. The bacteria’s used in their study 

were Salmonella enterica, Bacillus cereus, and Escherichia 

coli. However, the drawback of reported bacterial detection 

was the assay was incapable to facilitate specificity of detection 

among bacterial species. However, the paper explained that 

the nonspecificity of the chromatic platform can benefit in 

evaluating food freshness where, the presence of any type of 

bacteria can be reported. 

VII. APPLICATIONS IN ELECTRONIC NOSE 

The development of an “electronic nose” for pathogen detection 

has received considerable attention in recent years. Conducting 

polymers have also been used as detectors in electronic 

nose systems. When gas is adsorbed by the sensor, conducting 

organic polymer sensors exhibit a change in resistance, which 

is sensed and delivered as the output. 

Conducting polymer-based e-nose sensor for foodborne 

pathogen detection has been reported by many researchers. 

Magan et al. [51] used Bloodhound BH114, an electronic 

nose unit including 14 conducting polymer sensors, to detect the 

volatile profiles produced by uninoculated skimmed milk media 

or that inoculated with bacteria (Pseudomonas aureofaciens, 

P. fluorescens, Bacillus cereus) or yeasts. It has reported that 

using discriminant function analyses it was possible to separate 

unspoiled milk and that containing spoilage bacteria or yeasts. 

The sensor array used was a useful discriminator of microbial 

volatile profiles. The paper discussed the potential for using an 

electronic nose system for early detection of microbial spoilage 

of milk-based products. Balasubramanian et al. [52], used a 

commercially available Cyranose-320 electronic nose system 

to identify Salmonella Typhimurium in inoculated beef samples. 

An electronic nose containing an array of 32 conducting 

polymer sensors was used to obtain the odor patterns of the 

headspace of the meat samples. The volatile organic compounds 

emanating from vacuum-packaged beef strip was analyzed. 

Their results proved that the electronic nose system was able to 

identify meat samples contaminated with . Typhimurium at a 

population concentration level cfu/g. 

Arshak et al., reported the use of an array of conducting 

polymer nanocomposite sensors containing both carbon black 

and polyaniline to detect and identify the foodborne bacterial 

pathogens such as, Salmonella spp., Bacillus cereus, and Vibrio 

parahaemolyticus through production of an individual response 

pattern for each bacterium [53]. Four sensor materials were 

used to analyze the bacteria vapors. The first material consisted 

of 20% wt. short chain polyaniline (emeraldine salt) grafted to 

lignin (PgL). The next three materials contained polyethylene 

adipate (PEA) and hypermer PS3 surfactant with 10%, 15%, and 

20% w/w of polyaniline loaded carbon black , respectively. 

It has been reported that the PgL sensor produced the 

highest response when exposed to vapors given off Salmonella 

with a 70% drop in baseline voltage. However, it did not return 

back to its original baseline voltage afterwards. The sensor’s 

responses to B. cereus and Vibrio were similar showing that this 

sensor could not be used on its own as a means to differentiate between 

these three bacteria. The sensor with 10 w/w% 

produced the highest response to each bacterium. This was 

followed by the sensor with 15% , while the lowest 

response was obtained from the sensor with % . 

Their results showed that sensors with lower volume fraction of 

conducting particles have higher sensitivity. Their work demonstrates 

the potential application for the on-site identification of 

food borne pathogens where these sensors could be interfaced 

with handheld devices to quantify emissions emanating from 

samples of contaminated foods. 

VIII. LAB-ON-CHIP 

Recently, Cretich et al. [54] demonstrated that copoly 

(DMA-NAS-MAPS) coated polydimethylsiloxane (PDMS) 

slides coupled to PDMS can be used to produce microcells 

that combines the advantages of microarray technology and 

microfluidics for the development of lab-on-chip devices. The 

coating PDMS allowing covalent binding of biomolecules 

and the coating was based on adsorption of a copolymer, 

copoly (DMA-NAS-MAPS), bearing functional groups. The 

copoly (DMA-NAS-MAPS) coated PDMS slides were used as 

flexible components of a microcell in semi-automated DNA 

microarray experiments for rapid food pathogen identification. 

The polymer is synthesized by free radical polymerization; it 

self-adsorbs onto the PDMS very rapidly, typically in 30 min, 

without any PDMS surface pretreatment. PDMS slides coated 

by copoly (DMANAS-MAPS) covalently bind amino-modified 

DNA fragments and have been tested in bacterial genotyping 

experiments. On a copoly (DMA-NAS-MAPS) coated PDMS 

slide, probes for detection of S. aureus and Listeria were spotted 

in 4 4 subarrays. The use of a back-and-forward microflow 

of 2 L/s of the PCR products dissolved in the hybridization 

buffer allowed shortening the hybridization time from 2 h (in 

the conventional static mode) to 800 s. The results showed 

the signals of the sample are specific and the background was 

acceptable. Also, the paper suggested that PDMS can be easily 

modified in every laboratory as its functionalization does not 

require sophisticated equipments, harsh conditions, or organic 

solvents. 

IX. CONCLUSION 

Although many conducting polymer-based biosensors for 

foodborne pathogen detection has been published in recent 

years, only very few applications to food samples have been reported 

to date. Among other conducting polymers, polyaniline, 

and polypyrrole were most extensive reported and polypyrrole 

was found to be a better choice for DNA biosensors. Foodborne 

pathogen detection based on electrochemical detection is preferred 

more than optical detection. To fabricate a conducting 

polymer-based biosensor, it is not only important to consider 

the properties of conducting polymers, but the method of 



immobilization plays a vital role. Therefore, by making use of 

conducting polymers with suitable immobilization technique, 

it is possible to develop a novel biosensor to detect foodborne 

pathogen detection in real time. Also, the use of nanomaterials/nanoparticles 

as a composite with conducting polymer 

would lead to the fabrication of biosensors and many other 

nanoelectronic devices and the basic requirements of biosensor 

like, enhanced sensitivity and very low detection limit can also 

achieved. 

REFERENCES 

[1] WHO, , “The world health report, 2007.” Global public health security 

in the 21st century, World Health Organization, Geneva, Switzerland, 

2007. 

[2] M. Angelopoulos, “Conducting polymers in microelectronics,” IBM J. 

Res. Develop., vol. 45, no. 1, pp. 57–75, 2001. 

[3] T. Ito, H. Shirakawa, and S. Ikeda, “Simultaneous polymerization and 

formation of polyacetylene film on surface of concentrated soluble 

Ziegler-type catalyst solution,” J. Polym. Sci. Pol. Chem., vol. 12, no. 

1, pp. 11–20, 1974. 

[4] H. Shirakawa, E. J. Louis, A. G. Macdiarmid, C. K. Chiang, and A. 

J. Heeger, “Synthesis of electrically conducting organic polymers: 

Halogen derivatives of polyacetylene, (CH) x,” J. Chem. Soc.-Chem. 

Commun., no. 16, pp. 578–580, 1977. 

[5] J. C. Chiang and A. G. Macdiarmid, “Polyaniline-protonic acid doping 

of the emeraldine form to the metallic regime,” Synth. Met., vol. 13, no. 

1–3, pp. 193–205, 1986. 

[6] F. Faridbod, M. R. Ganjali, R. Dinarvand, and P. Norouzi, “Developments 

in the field of conducting and non-conducting polymer based 

potentiometric membrane sensors for ions over the past decade,” Sensors, 

vol. 8, no. 4, pp. 2331–2412, 2008. 

[7] R. J. Geise, J. M. Adams, N. J. Barone, and A. M. Yacynych, “Electropolymerized 

films to prevent interferences and electrode fouling in 

biosensors,” Biosens. Bioelectron., vol. 6, no. 2, pp. 151–160, 1991. 

[8] F. F. Fang, H. J. Choi, and J. Joo, “Conducting polymer/clay nanocomposites 

and their applications,” J. Nanosci. Nanotechnol., vol. 8, no. 4, 

pp. 1559–1581, 2008. 

[9] M. V. Murugendrappa and M. Prasad, “Chemical synthesis, characterization, 

and direct-current conductivity studies of polypyrrole/gamma-Fe 

O composites,” J. Appl. Polym. Sci., vol. 103, no. 5, 

pp. 2797–2801, 2007. 

[10] B. D. Malhotra, A. Chaubey, and S. P. Singh, “Prospects of conducting 

polymers in biosensors,” Anal. Chim. Acta., vol. 578, no. 1, pp. 59–74, 

2006. 

[11] F. R. R. Teles and L. R. Fonseca, “Applications of polymers 

for biomolecule immobilization in electrochemical biosensors,” 

Mater. Sci. Eng. C—Biomimetic Supramol. Syst., vol. 28, no. 8, pp. 

1530–1543, 2008. 

[12] Y. H. Xiao and C. M. Li, “Nanocomposites: From fabrications to 

electrochemical bioapplications,” Electroanalysis, vol. 20, no. 6, pp. 

648–662, 2008. 

[13] J. Galandova and J. Labuda, “Polymer interfaces used in electrochemical 

DNA-based biosensors,” Chem. Pap., vol. 63, no. 1, pp. 1–14, 2009. 

[14] S. Pal and E. C. Alocilja, “Electrically active polyaniline coated magnetic 

(EAPM) nanoparticle as novel transducer in biosensor for detection 

of Bacillus anthracis spores in food samples,” Biosens. Bioelectron., 

vol. 24, no. 5, pp. 1437–1444, 2009. 

[15] T. R. Ahuja and D. Kumar, “Recent progress in the development of 

nano-structured conducting polymers/nanocomposites for sensor applications,” 

Sens. Actuator B—Chem., vol. 136, no. 1, pp. 275–286, 

2009. 

[16] Y. F. Ma, S. R. Ali, A. S. Dodoo, and H. X. He, “Enhanced sensitivity 

for biosensors: Multiple functions of DNA-wrapped single-walled 

carbon nanotubes in self-doped polyaniline nanocomposites,” J. Phys. 

Chem. B, vol. 110, no. 33, pp. 16359–16365, 2006. 

[17] O. Güven, “Radiation-induced conductivity control in polyaniline 

blends/composites,” Radiat. Phys. Chem., vol. 76, no. 8–9, pp. 

1302–1307, 2007. 

[18] A. S. Haynes and P. I. Gouma, “Electrospun conducting polymer-based 

sensors for advanced pathogen detection,” IEEE Sensors J., vol. 8, no. 

6, pp. 701–705, 2008. 

[19] J. J. Langer and K. Langer, “Polyaniline nanobiodetector,” Rev. Adv. 

Mater. Sci., vol. 10, no. 5, pp. 434–436, 2005. 

[20] A. Morrin, O. Ngamna, A. J. Killard, S. E. Moulton, M. R. Smyth, 

and G. G. Wallace, “An amperometric enzyme biosensor fabricated 

from polyaniline nanoparticles,” Electroanalysis, vol. 17, no. 5–6, pp. 

423–430, 2005. 

[21] A. Morrin, F. Wilbeer, O. Ngamna, S. E. Moulton, A. J. Killard, G. 

G. Wallace, and M. R. Smyth, “Novel biosensor fabrication methodology 

based on processable conducting polyaniline nanoparticles,” 

Electrochem. Commun., vol. 7, no. 3, pp. 317–322, 2005. 

[22] C. Dispenza, M. Leone, C. Lo Presti, F. Librizzi, G. Spadaro, and V. 

Vetri, “Optical properties of biocompatible polyaniline nano-composites,” 

J. Non-Cryst. Solids, vol. 352, no. 36–37, pp. 3835–3840, 2006. 

[23] F. Devreux, F. Genoud, M. Nechtschein, and B. Villeret, “Electronspin-resonance 

investigation of polarons and bipolarons in conducting 

polymers—The case of polypyrrole,” Synth. Met., vol. 18, no. 1–3, pp. 

89–94, 1987. 

[24] A. O. Patil, A. J. Heeger, and F. Wudl, “Optical-properties of conducting 

polymers,” Chem. Rev., vol. 88, no. 1, pp. 183–200, 1988. 

[25] A. Ramanaviciene and A. Ramanavicius, “Application of polypyrrole 

for the creation of immunosensors,” Crit. Rev. Anal. Chem., vol. 32, 

no. 3, pp. 245–252, 2002. 

[26] A. Ramanavicius, A. Ramanaviciene, and A. Malinauskas, “Electrochemical 

sensors based on conducting polymer—polypyrrole,” Electrochim. 

Acta., vol. 51, no. 27, pp. 6025–6037, 2006. 

[27] M. I. Rodriguez and E. C. Alocilja, “Embedded DNA-polypyrrole 

biosensor for rapid detection of Escherichia coli,” IEEE Sensors J., 

vol. 5, no. 4, pp. 733–736, 2005. 

[28] K. Arora, N. Prabhakar, S. Chand, and B. D. Malhotra, “Immobilization 

of single stranded DNA probe onto polypyrrole-polyvinyl sulfonate for 

application to DNA hybridization biosensor,” Sens. Actuator B-Chem., 

vol. 126, no. 2, pp. 655–663, 2007. 

[29] D. Zanuy and C. Aleman, “DNA-conducting polymer complexes: A 

computational study of the hydrogen bond between building blocks,” 

J. Phys. Chem. B., vol. 112, no. 10, pp. 3222–3230, 2008. 

[30] L. C. Clark, “Monitor and control of blood and tissue oxygen tensions,” 

Trans. Amer. Soc. Artif. Internal Organs, vol. 2, p. 41, 1956. 

[31] T. Vo-Dinh and B. Cullum, “Biosensors and biochips: Advances in biological 

and medical diagnostics,” Fresenius J. Anal. Chem., vol. 366, 

no. 6–7, pp. 540–551, 2000. 

[32] E. Tully, S. P. Higson, and R. O. Kennedy, “The development of a 

‘labeless’ immunosensor for the detection of Listeria monocytogenes 

cell surface protein, internalin B,” Biosens. Bioelectronics., vol. 23, no. 

6, pp. 906–912, 2008. 

[33] A. De Crombrugghe, S. Yunus, and P. Bertrand, “Grafting and characterization 

of protein on polyaniline surface for biosensor applications,” 

Surf. Interface Anal., vol. 40, no. 3–4, pp. 404–407, 2008. 

[34] A. I. Minett, J. N. Barisci, and G. G. Wallace, “Coupling conducting 

polymers and mediated electrochemical responses for the detection of 

Listeria,” Anal. Chim. Acta., vol. 475, no. 1–2, pp. 37–45, 2003. 

[35] S. Ghosh, D. Sarker, and T. N. Misra, “Development of an amperometric 

enzyme electrode biosensor for fish freshness detection,” Sens. 

Actuators B: Chem., vol. 53, no. 1–2, pp. 58–62, 1998. 

[36] V. Velusamy, K. Arshak, O. Korostynska, K. Oliwa, and C. Adley, 

“Design of a real time biorecognition system to detect foodborne 

pathogens—DNA biosensor,” in Proc. SAS 2009, New Orleans, LA, 

2009, pp. 38–41. 

[37] L. Yang and R. Bashir, “Electrical/electrochemical impedance for rapid 

detection of foodborne pathogenic bacteria,” Biotechnol. Adv., vol. 26, 

no. 2, pp. 135–150, 2008. 

[38] Z. Muhammad-Tahir and E. C. Alocilja, “Fabrication of a disposable 

biosensor for Escherichia coli O157:H7 detection,” IEEE Sensors J., 

vol. 3, no. 4, pp. 345–351, 2003. 

[39] Z. Muhammad-Tahir and E. C. Alocilja, “A disposable biosensor for 

pathogen detection in fresh produce samples,” Biosys. Eng., vol. 88, 

no. 2, pp. 145–151, 2004. 

[40] E. C. Alocilja and Z. Muhammad-Tahir, “Biosensor for detecting 

bacteria uses fluid electrically conductive polymer bound to capture 

reagent that captures analyte in sample and migrates to capture zone 

where complexed analyte is captured by another capture reagent.,” 

Patent WO2003069301-A; US2003153094-A1; WO2003069301-A2; 

AU2002359776-A1; AU2002359776-A8, 2003. 

[41] S. Pal, W. Ying, E. C. Alocija, and F. P. Downes, “Sensitivity and specificity 

performance of a direct-charge transfer biosensor for detecting 

Bacillus cereus in selected food matrices,” Biosys. Eng., vol. 99, no. 4, 

pp. 461–468, 2008. 

[42] K. Arora, N. Prabhakar, S. Chand, and B. D. Malhotra, “Escherichia 

coli genosensor based on polyaniline,” Anal. Chem., vol. 79, no. 16, 

pp. 6152–6158, 2007. 



[43] M. T. Morgan, G. Kim, D. Ess, A. Kothapalli, B. K. Hahm, and A. 

Bhunia, “Binding inhibition assay using fiber-optic based biosensor for 

the detection of foodborne pathogens,” in Proc. Adv. Nondestructive 

Evaluation I, Pts 1 and 2, 2006, pp. 1145–1150. 

[44] S. H. Ko and S. A. Grant, “A novel FRET-based optical fiber biosensor 

for rapid detection of Salmonella typhimurium,” Biosens. Bioelectron., 

vol. 21, no. 7, pp. 1283–1290, 2006. 

[45] S. Varkey, A. C. Cannons, and D. V. Lim, “Enhanced detection of DNA 

fragments with an evanescent biosensor using a signal amplification 

system,” in Proc. Abstracts Gen. Meeting Amer. Soc. Microbiol., 2002, 

vol. 102, p. 145. 

[46] R. W. Carpick, D. Y. Sasaki, M. S. Marcus, M. A. Eriksson, and A. 

R. Burns, “Polydiacetylene films: A review of recent investigations 

into chromogenic transitions and nanomechanical properties,” J. Phys. 

—Condes. Matter., vol. 16, no. 23, pp. R679–R697, 2004. 

[47] Y. Fan, L. G. Zhang, F. Y. Hou, B. L. Ma, D. Z. Shen, and Y. J. Li, 

“Studies on recognition and dynamic analysis of polydiacetylene Langmuir-Schaefer 

films functionalized with glycolipid,” Chem. J. Chin. 

Univ.—Chin., vol. 24, no. 4, pp. 657–661, 2003. 

[48] Y. L. Su, J. R. Li, L. Jiang, and J. Cao, “Biosensor signal amplification 

of vesicles functionalized with glycolipid for colorimetric detection of 

Escherichia coli,” J. Colloid Interface Sci., vol. 284, no. 1, pp. 114–119, 

2005. 

[49] J. Song, Q. Cheng, S. M. Zhu, and R. C. Stevens, ““Smart” materials 

for biosensing devices: Cell-mimicking supramolecular assemblies and 

colorimetric detection of pathogenic agents,” Biomed. Microdevices, 

vol. 4, no. 3, pp. 213–221, 2002. 

[50] L. Silbert, I. Ben Shlush, E. Israel, A. Porgador, S. Kolusheva, and 

R. Jelinek, “Rapid chromatic detection of bacteria by use of a new 

biomimetic polymer sensor,” Appl. Environ. Microbiol., vol. 72, no. 11, 

pp. 7339–7344, 2006. 

[51] N. Magan, A. Pavlou, and I. Chrysanthakis, “Milk-sense: A volatile 

sensing system recognises spoilage bacteria and yeasts in milk,” Sens. 

Actuator B—Chem., vol. 72, no. 1, pp. 28–34, 2001. 

[52] S. Balasubramanian, S. Panigrahi, C. M. Logue, M. Marchello, and 

J. S. Sherwood, “Identification of Salmonella-inoculated beef using a 

portable electronic nose system,” J. Rapid Methods Automat. Micro., 

vol. 13, no. 2, pp. 71–95, 2005. 

[53] K. Arshak, C. Adley, E. Moore, C. Cunniffe, M. Campion, and J. 

Harris, “Characterisation of polymer nanocomposite sensors for 

quantification of bacterial cultures,” Sens. Actuators B: Chem., vol. 

126, no. 1, pp. 226–231, 2007. 

[54] M. Cretich, V. Sedini, F. Damin, G. D. Carlo, C. Oldani, and M. 

Chiari, “Functionalization of poly(dimethylsiloxane) by chemisorption 

of copolymers: DNA microarrays for pathogen detection,” Sens. 

Actuators B: Chem., vol. 132, pp. 258–264, 2008. 

Khalil Arshak received the B.Sc. degree from 

Basrah University, Iraq, in 1969, the M.Sc. degree 

from Salford University, Salford, U.K., in 1979, and 

the Ph.D. and D.Sc. degrees from Brunel University, 

Uxbridge, U.K., in 1986 and 1998, respectively. 

He joined the University of Limerick in 1986, 

where he leads the microelectronic and semiconductor 

research group. He has authored more than 

400 research papers in the area of microelectronics 

and thin- and thick-film technology. His current 

research interests include lithography process modeling, 

handheld DNA biosenor development, and application specific integrated 

circuit design. 

Vijayalakshmi Velusamy received the B.E. degree 

in electrical and electronics engineering from 

Bharathiar University, Coimbatore, India, in 2002 

and the M.Sc. (Eng.) degree in micro and nanotechnology 

from the University of Ulster , Northern 

Ireland, U.K., in 2007. She is currently working towards 

the Ph.D. degree at the University of Limerick. 

Her areas of interest include biosensors and, in particular, 

development of handheld DNA sensors for 

the foodborne pathogen detection. 

Olga Korostynska received the B.Sc. and M.Sc. 

degrees from the National Technical University, 

Ukraine (KPI) in 1998 and 2000, respectively, in 

biomedical electronics, and the Ph.D. degree from 

the University of Limerick, Limerick, Ireland, in 

2003. 

Her research interests are in thin- and thick-film 

technologies, material properties characterization, 

and thin/thick film sensors. 

Kamila Oliwa-Stasiak received the B.Sc. degree in 

medical biotechnology from Ludwik Rydygier Collegium 

Medicum, Bydgoszcz, Poland, in 2004 and 

the M.Sc. degree in biotechnology (microbiology) 

from the University of Warsaw, Warsaw, Poland, in 

2006. Currently, she is working towards the Ph.D. 

degree at the Microbiology Laboratory, University 

of Limerick, Limerick, Ireland. 

Her area of interest is developing a DNA-bsed 

biosensor for the detection and quantification of the 

Bacillus cereus group species in milk products. 

Catherine Adley received the Ph.D. degree from the 

National University of Ireland, Dublin. 

She has been with the London School of Hygiene 

and Tropical Medicine and at The University 

of Surrey, U.K. She is Head of the Department 

of Chemical and Environmental Sciences at the 

University Limerick. In the U.S., she worked at 

Cold Spring Harbour Laboratory New York and 

at Boston University and spent a sabbatical at the 

Pasteur Institute France. She is an elected member of 

the Royal Dublin Society Science and Technology 

Committee, and a member of the Scientific Committee of the Food Safety 

Authority of Ireland. She is the national delegate to the EU COST program for 

food and agriculture. COST is an intergovernmental framework for European 

Cooperation in Science and Technology. Her research interests are in rapid 

microbial testing systems.

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