Multi-functional polymer scaffolds as biosensors for detection of ethanol and organophosphorous pesticides and as fluorescent probes for cell imaging purposes

Kesik Mancar, Melis
Overwhelming characteristics of conducting polymers led to opening a new research field in the last decades. There are a number of application areas of CPs which attracted keen interest of scientific world. The two main concepts of this thesis are conducting polymer based biological sensors and cell imaging study. Accordingly, the use of multi-functional polymers as biosensors for detection of ethanol and organophosphorous (OPs) pesticides and as different multi-purpose fluorescent probes for cell imaging studies were discussed in three different parts. In the first study, a CP (poly(TIFc-co-BEDOA-6-poly(L-Boc)) containing polypeptide and ferrocene side chains was utilized as an immobilization matrix for AOx biosensor construction. Newly designed biosensor which combined the advantages of each component was tested as an ethanol sensing system offering fast response time, wide linear range and low detection limit with a high sensitivity. The capability of the biosensor in determining ethanol content in alcoholic beverages was also demonstrated. In the second study, a novel amperometric biosensor based on a CP (poly(SNS-NH2)) using MWCNT modified electrode was developed for the detection of paraoxon, parathion and chlorfenvinphos as model OPs. Inhibitory effect of OPs on AChE activity were investigated. The fabricated biosensor was tested for the detection of pesticides in fortified tap water samples. The results were found to be in good agreement with the ones determined by HPLC/DAD technique. In the third study, a fluorescent and functional monomer, PIP and an antibody labeling kit (CF555) were merged on the same scaffold to generate the proposed bioprobe offering multicolor cell images. The aim was to achieve targeted imaging of CD44 positive U87-MG cancer cells and determine specific cellular labeling via fluorescence imaging and flow cytometry experiments.