Sensitive voltammetric sensor based on silver dendrites decorated polythiophene nanocomposite: Selective determination of L-Tryptophan

Abstract

This present work describes the direct electrochemical determination of L-Tryptophan (L-Try) using polythiophene (PT) with silver (Ag) dendrites composite formed via electrostatic interaction. In the composite, Ag dendrites provide the energy to speedup chemical reaction by the presence of cationic free radicals and found attached with the backbone of PT. Furthermore, the sulfur groups of PT help in the formation of a stable product, and keeping them in same phase. The PT-Ag modified Glassy Carbon Electrode (GCE) revealed excellent electrochemical activity towards the oxidation of L-Try with the linear response in the concentration range of 200 nM–400 μM with detection limit of 20 nM. The fabricated sensor demonstrated the selective determination of L-Try in presence of foreign substances and the PT-Ag modified interface lead to the development of novel biosensor with high sensitivity and good stability which is mainly attributable to increased surface area of the composite. The characteristics of the PT-Ag hybrid nanocomposite proved the determination of L-Try in real food samples like soybeans extract with satisfactory results.