Bismuth oxide and nitrogen-doped reduced graphene oxide co-modified glassy carbon electrode to perform sensitive electrochemical sensing and determination of chrysin in pharmaceutical capsules

A bismuth oxide- nitrogen doped reduced graphene oxide/glassy carbon electrode (Bi2O3-NRGO/GCE) was prepared for the detection of the flavonoid drug chrysin in pharmaceutical capsules, for the first time. Bi2O3 nanosheets synthesized by a hydrothermal method, were ultrasonically mixed with NRGO, and a simple and efficient Bi2O3-NRGO/GCE composite was prepared. The composites were characterized by various methods. Cyclic voltammetry and electrochemical impedance techniques were used to study the electrochemical sensing performance of the composites-modified electrode surface. The electrochemical performance and optimal detection conditions of chrysin on Bi2O3-NRGO/GCE were investigated by differential pulse voltammetry (DPV). The oxidation peak current of chrysin has a linear relationship with its concentration, in the range of 0.01–10 μM, with a detection limit of 2.0 nM. Bi2O3-NRGO/GCE also has good selectivity for chrysin, which is not interfered with by common inorganic salts and common organic substances, or by structurally similar substances. The composite electrode also has good repeatability, reproducibility and stability. It shows that utilizing Bi2O3 and NRGO binary complexes modified electrodes for ultrasensitive chrysin sensing is a simple and convenient detection method, with promising applicability in the development of pharmaceutical component sensing technology.