Green electrodeposition of gold hierarchical dendrites of pyramidal nanoparticles and determination of azathioprine

Gold hierarchical dendrites consisting of an array of parallel-arranged pyramidal nanoparticles were electrodeposited in the presence of lysine on a gold surface and characterized by scanning electron microscopy. The kinetics of azathioprine electroreduction on the dendrites' surface was studied in a phosphate buffer solution, pH 7.40 by voltammetric measurements. Azathioprine was electroreduced on the dendrites' surface at a lower potential and with a higher rate, compared to a polycrystalline smooth gold surface through an irreversible process. Based on the results, a sensitive electrochemical sensor was designed based on the gold hierarchical dendrites for the determination of azathioprine. A differential pulse voltammetric procedure was developed for determination of azathioprine. A linear dynamic range of 0.095-900 μmol L−1 with a calibration sensitivity of 0.14 A L mol−1 cm−2, and a detection limit of 0.090 μmol L−1 was obtained. The differential pulse voltammetry method was also applied to the analysis of azathioprine tablets.