A novel and sensitive Cu2ZnSnS4 quantum dot–based non–enzymatic glucose sensor

Abstract

Copper–chalcogenide quantum dots (QDs) featuring big surface–to–volume ratio, capably electrochemical activities, highly electrical conductivity, natural abundance, low cost and nontoxicity fitted quite well as electrocatalyst for non–enzymatic glucose oxidizing sensor. Presently, 1–octadecanamine–capped quaternary Cu2ZnSnS4 QDs (CZTS QDs) with size of 4–6 nm, fabricated by facile solvothermal approach with cost–effective and non–toxic precursors, were used as a novel materials modified onto fluorine doped tin oxide (FTO) glass to develop CZTS QD–based non–enzymatic glucose biosensor for first time. And, the route of partial removal of 1–octadecanamine ligand has been established to enhance the sensitivity from 1561 to 2503 μA mM–1 cm–2 for CZTS QD–based non–enzymatic glucose biosensor, ascribed fundamentally to enlarging active surface area, reducing the charge transfer resistance, improving glucose diffusion coefficient and advancing catalytic rate constant. The performance of CZTS QD–based non–enzymatic sensor in high sensitivity, broad linear range, short respond time, low detection limit, precise selectivity, long–time stability, good reproducibility and practical application in blood serum determination deserved the potential candidate for electrochemically non–enzymatic glucose biosensor in future.