Highly selective detection of dopamine in the presence of ascorbic acid and uric acid using thioglycolic acid capped CdTe quantum dots modified electrode

In this work, cadmium telluride (CdTe) quantum dots (QDs) have been successfully applied for construction of a novel chemically modified electrode for determination of dopamine (DA) in the presence of ascorbic acid (AA) and uric acid (UA). The small CdTe QDs were synthesized by using a wet chemical routes in the presence of thioglycolic acid (TGA), as capping agent at pH 9.5, having particle diameters of 1–3 nm. The synthesized QDs were immobilized on the surface of gold disk electrode by self assembly method in dark conditions for 30 h and electrochemically characterized. The modified CdTe QDs-based electrode afforded the simultaneous detection of these three compounds with wide peak separations, which allowed the interferences to be masked with applied potential. Using a potential window of 0–350 mV, where only dopamine was electroactive, a detection limit of 8.27 × 10−9 M and 1.30 × 10−9 M were calculated from square wave voltammetry and amperometry, respectively.