Folic-Acid-Modified Conducting Polymer: Electrochemical Detection of the Cell Attachment

Abstract

Here, postfunctionalization and bioapplication of a π-conjugated polymer named 4-[4H-dithieno(3,2-b:2′,3′-d)pyrrol-4-yl]aniline (DTP-aryl-NH2) are reported, which is successfully synthesized via electropolymerization onto the glassy carbon electrode. Folic acid (FA) is used to modify the amino functional polymer via N-(3-dimethylaminopropyl)-N′-ethylcarbodiimide hydrochloride/N-hydroxysuccinimide chemistry for the further steps. The selective adhesion of folate receptor positive cells on the surface is followed by the electrochemical methods. Cyclic voltammetry and electrochemical impedance spectroscopy have been used to characterize stepwise modification of the electroactive surface. After optimization studies such as scan rate during the polymer deposition, FA amount for the efficient surface targeting, incubation time with the cells etc., analytical characterization is carried out. The surface morphologies at each step are imaged by using fluorescence microscopy. Electropolymerization of 4-[4H-dithieno(3,2-b:2′,3′-d)pyrrol-4-yl]aniline (DTP-aryl-NH2) is carried out and folic acid was modified via functional amino groups on resulted conducting polymer. This biorecognition layer is conducted to the cell attachment and detection applications by using HeLa (folate receptor positive) and A549 (folate receptor negative) cell lines. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.