Photonic crystals in biology

Poster Session, Tuesday, June 15
Theme A1 - B702
IONIC LIQUID DOPED ELECTROSPUN POLYMER COMPOSITE NANOFIBERS
FOR COPPER(II) SENSING
Merve Zeyrek a* , Kadriye Ertekin a , Mustafa Göçmentürk a , Yavuz Ergün a , Mehtap Özdemir b , Erdal Çelik b,c
a
University of Dokuz Eylul, Faculty of Arts and Sciences, Department of Chemistry, 35160, Izmir, Turkey
b
University of Dokuz Eylul, Faculty Engineering, Department of Metallurgical and Materials Engineering, 35160, Izmir, Turkey
c University of Dokuz Eylul, Center for Fabrication and Application of Electronic Materials (EMUM), 35160, Izmir, Turkey
Abstract- In this work Copper(II) sensing nanofibers were produced. Fluorescence sensing agent and auxiliary additives were
doped into PMMA and EC matrices. Presence of ionic liquid in the matrix material enhanced electrospinning process and
provided higher analytical signal.
Recently electrospinning has gained much
attention as a simple and reliable process to produce
polymer and composite nanofibers, which have small
diameter and high aspect ratio and have different
types of applications including tissue engineering,
biocompatible materials, filters, optical sensor design
and drug delivery. For a typical electrospinning setup
as shown in Fig. 1, a high voltage, usually more than
5 kV, is applied to the polymer based composite in a
spinneret so that free charges accumulate at the
liquid-air interface of the capillary. At a critical
voltage, the repulsive force within the charged
polymer solution is larger than the surface tension and
a jet erupts from the tip of the spinneret. As the jet
travels through the air, it solidifies leaving behind a
polymer fiber to be collected on an electrically
grounded support [1]. Electrospun fibers can be
functionalized by the use of proper indicator and
auxiliary additives for desired purposes.
amount of phase transfer agent and varying amounts
of plasticizer (DOP) and ionic liquid in 1.5mL of
EtOH/CH 3 Cl (v/v 3/1). EC based solutions were
prepared by a similar protocol.
Figure 2. Chemical structure of MY10 dye
Electrospinning was performed at 25 kV voltage
and at 0.3 mL/h flow rate. SEM micrographs of
PMMA based nanofibers were shown in Fig. 3. Upon
exposure to Cu 2+ the MY10 dye exhibited an
emission based signal change at 530 nm in direction
of signal decrease. The fiber diameters were
measured between 634-823 nm for 25% DOP, 25%
IL and 50% PMMA containing composites. Photocharacterization,
electrospinning fabrication, and
sensing capability of PMMA and EC based fibers are
discussed.
Figure 1. A simplified schematic of the electrospinning
process.
Copper is the third most abundant element in the
human body and is essential in several biological
pathways including electron transport, O 2 metabolism
and enzymatic catalysis. Oter et al. that offered sensor
exhibited remarkable fluorescence intensity
quenching upon exposure to Cu 2+ ions at pH 4.0 in
the concentration range of 1.0×10 −9 to 3.0×10 −4 M
[Cu 2+ ] [2]. In this work the Cu 2+ sensitive dye; N’-3-
(4(dimethylamino)phenyl)allylidene)isonicotinohydra
zide) (MY10) has been used as sensing agent (See
Fig.2). The MY10 dye was doped into poly-methylmethacrylate
together with ionic liquid and other
additives. Composite fibers were fabricated by
electrospinning and characterized by Scanning
Electron Microscopy (SEM). Polymer solutions were
prepared by mixing 240 mg of poly(methyl
methacrylate), 1 mg of MY10 dye, equivalent
Figure 3. An SEM micrograph PMMA based nanofiber
The preliminary results show that these sensing
agents have an order of magnitude higher sensitivity
to the Cu 2+ than sensor slides formed from continuous
thin films. This is believed to be due to the higher
surface area to volume ratio of the electrospun
nanofibrous materials.
* Corresponding author: mervezeyrek@gmail.com
[1] K. Tong, C. Xu, Q. Wang, B. Gu, K. Zheng, L. Ye and
X. Li, Chin.Phys.Lett. 25, 4453 (2008).
[2] O. Oter, K. Ertekin, C. Kırılmıs and M. Koca, Analytica
Chimica Acta 584, 308–314 (2007).
6th Nanoscience and Nanotechnology Conference, zmir, 2010 395