Advances in biosensors: principle, architecture and applications

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need the control the physical and chemical parameter of environment. However the major
limitation with cell based biosensor are the stability of the cell, which depends on various
conditions such as the sterilization, lifetime, biocompatibility and etc. Another issue that
governs the success of a cell based sensor are depends primarily ion selectivity, in which cell
based sensor has poor selectivity of microbial sensor due to the multireceptor behavior of the
intact cells (Belkin and Gu 2010). Despite these pitfalls the cell based biosensor still favorable
among the researcher due to the advantages over the enzymes based biosensor. The cell based
biosensor are less sensitive to inhibition by solutes and are more tolerant of suboptimal pH
and temperature values than enzyme based biosensor, though they must not exceed the narrow
range in case of the cells dying, a longer lifetime can be expected than with the enzymatic
sensors and they are much cheaper because active cells do not need to be isolated (Struss et al.
2010). Literature revealed that, cell based sensor have become an emerging tools for medical
diagnostics (i.e. such as disease detection), environmental analysis, food quality control,
chemical-pharmaceutical industry and drugs detection (Veiseh et al. 2007, Banerjee and
Bhunia 2009, Banerjee and Bhunia 2010, Wang, T et al. 2010, Melamed et al. 2012, Bohrn et
al. 2012, Liu, Q et al. 2012 ). Similarly, Shinde et al. 2012 conclude that cell based biosensor
is envisioned to be an emerging frontier in the area of nano-diagnotics due to their attractive
characteristic.
Biomimetic sensor
A biomimetic biosensor is an artificial or synthetic sensor that mimics the function of a
natural biosensor. These can include aptasensors, where aptasensors use aptamers as the
biocomponent (David et al. 2008). Aptamers were reported for the first time in the early
1990s where described as artificial nucleic acid ligands. Aptamers were thus chemically
related to nucleic acid probes, but behaved more like antibody and showing surprising
versatility compared to other bio-recognition components (Schneider et al 2010, Brys et al.
2007). Aptamer are synthetic strands of nucleic acid that can be designed to recognize amino
acids, oligosaccharides, peptides, and proteins. An aptamer has few advantages over antibody
based biosensor such as high binding efficiency, avoiding the use of animal (i.e reduced
ethical problem), smaller and less complex, and etc. However, common challenge facing
aptasensor is that they inherent the properties of nucleic acids such as structural pleomorphic
and chemical simplicity which reduced the assay efficiency and also increase its production
cost. Subsequently, some effort has been directed towards characterization and optimization
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