Amperometric Detection of Glucose Using a Conjugated Polyelectrolyte Complex with Single-Walled Carbon Nanotubes

The conjugated polymer, poly[3-(3-N,N-diethylaminopropoxy)thiophene] (PDAOT), was synthesized and employed in the supramolecular functionalization of single-walled carbon nanotubes (SWNTs). Highly stable aqueous solutions of PDAOT−SWNT complexes were obtained after sonication under mildly acidic conditions. UV−vis absorption and Raman spectroscopy studies showed that the noncovalent functionalization did not change the nanotube structure and retained its inherent properties. The reactions of [Fe(CN6)]3−/4− redox couple on Au electrodes modified with PDAOT and the PDAOT−SWNT films were studied using electrochemical impedance spectroscopy and cyclic voltammetry. A lower electron-transfer resistance and higher current response were observed on the Au/PDAOT−SWNT electrode compared with the Au/PDAOT electrode. We prepared glucose biosensors by entrapping glucose oxidase (GOx) within the PDAOT and PDAOT−SWNT films. Under optimized conditions, the Au/PDAOT−SWNT/GOx biosensor exhibited fast current response to gl...