Electrochemical glucose biosensing via new generation DTP type conducting polymers/gold nanoparticles/glucose oxidase modified electrodes

The synthesis of derivatives of dithionepyrrole is a hot subject that has been studied extensively. In this study, a novel approach for constructing different glucose biosensors using conducting polymers of 4-(4H-dithyinol[3,2-b:2′,3′-d]pyroll-4-yl)aniline and 4-(4H-dithyinol[3,2-b:2′,3′-d]pyroll-4-yl)-[1,1′-biphenyl]-4-amine is proposed. After the synthesis and characterizations of the dithionepyrrole type monomers, they were used in glucose biosensing applications. The surface of gold electrode was modified with mercaptoethane sulfonic acid and p-aminothiophenol functionalized gold nanoparticles and aniline modified GOx. Electrochemical measurements were carried out by following the consumed oxygen due to the enzymatic reaction of glucose oxidase. DTP-Ph-NH2/AuNP/GOx and DTP-Ph-Ph-NH2/AuNP/GOx biosensors showed very good linearity between 0.1 and 2.5 mM, and 0.05 and 1 mM for glucose, respectively. LOD value was obtained for pDTP-Ph-NH2/AuNP/GOx as 5.00 × 10− 2 mM and for pDTP-Ph-Ph-NH2/AuNP/GOx as 9.86 × 10− 5 mM using S/N ratio. Optimization of molar ratio amount of AuNP/GOx, cycles amount to immobilize AuNP/GOx, conducting polymer thickness were examined. Finally, under optimized conditions, the amount of glucose in spiked human serum samples and recovery experiments were conducted.