An Electrochemical Sensor for the determination of Uric Acid based on CdSe Quantum Qots (QDs) / Graphene Oxide (GO) nanocomposite

A chemically modified electrode has been constructed based on CdSe QDs/GO nanocomposite and employed for the selective determination of Uric acid (UA) in 0.1M Phosphate buffer solution, (PBS, pH 7.0). Field emission scanning electron microscope (FESEM) was applied to characterize the surface morphology and the performance of the modified electrode was examined by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The results showed that the electrochemical sensor showed excellent electrocatalytic activity towards the oxidation of UA. Under optimum conditions, the linear range for the detection of UA is 1.7 x 10 M to 1.0 x 10 M and the detection limit was found to be 5.6 x 10 M (S/N = 3). The utility of the modified electrode in flow systems for the determination of UA was evaluated by hydrodynamic and chronoamperometric studies. The high sensitivity, selectivity, reproducibility and longterm stability of the CdSe QDs/GO nanocomposite modified electrode provided a sensing platform for the determination of UA.