Fabrication of the electrochemically reduced graphene oxide-bismuth nanoparticles composite and its analytical application for an anticancer drug gemcitabine

The present study explores an electroreduced graphene oxide-bismuth nanoparticles composite (Er-GOBi) as an electrochemical sensor for the determination of an anticancer drug, gemcitabine hydrochloride (GMB). The Er-GOBi interface was prepared by drop casting of bismuth nitrate-graphene oxide suspension on a glassy carbon electrode (GCE) followed by electro-reduction in the potential range of 0.6 V to −1.7 V. SEM, FTIR, EDAX and AFM techniques were employed for the characterization of prepared materials. Cyclic voltammetric and electrochemical impedance spectroscopic methods were used to understand the charge transfer properties of stepwise modification of Er-GOBi/GCE. GMB exhibited an irreversible oxidation peak at 1.144 V on Er-GOBi/GCE in phosphate buffer of pH 3. A 100-fold enhanced oxidation peak current was observed at Er-GOBi/GCE when compared to that at bare GCE. Sensing performance of ErGO-Bi/GCE was optimized by varying peak current dependent parameters. Linear relationship between the peak current and concentration of GMB was observed in the range of 0.1–51.1 μmol/L in differential pulse voltammetric method and 2.1–61.1 μmol/L in linear sweep voltammetric method. The practical utility of the proposed sensor, Er-GOBi/GCE was demonstrated by determining GMB in pharmaceutical formulations and spiked urine samples.