Decoration of Bi2O3NPs-AgNPs-ErGO as a first electrochemical nanosensor for sensitive determination of nelarabine in pharmaceutical dosage form and human serum samples

In view of the unquestionable necessity for rapid and accurate analysis of drug molecules to monitor patient overdose, numerous nanosensor-based technologies have been developed in addition to quality control of pharmaceutical manufacture and drug administration. In this regard, sensitive detection of a potent anticancer agent, nelarabine (NEL) was examined at the bare and modified glassy carbon electrode (GCE) with the help of differential pulse (DP) and cyclic voltammetry (CV) techniques. A unique and highly effective nanosensor was developed using a combination of bismuth (III) oxide nanoparticles (Bi₂O₃NPs), silver nanoparticles (AgNPs), and electrochemically reduced graphene oxide (ErGO) onto the GCE surface. The modified Bi₂O₃NPs-AgNPs-ErGO/GCE was characterized by scanning electron microscopy (SEM), CV, and electrochemical impedance spectroscopy (EIS) investigations. Influences of various parameters viz., loading of Bi₂O₃NPs, AgNPs, and GO on the modified GCE, electrolyte pH (PBS 7.0), accumulation potential (–0.2 V), and time (60 s), and scan rate (50 mV s⁻¹) were optimized for NEL response. An enhancement in the current responses toward the oxidation of NEL was observed with the Bi₂O₃NPs-AgNPs-ErGO/GCE compared to that noticed with bare GCE. The modified GCE affirmed high sensitivity, low limit of detection (LOD), excellent reproducibility, repeatability, and storage stability that clearly indicated the effective accuracy of the developed nanosensor. The linear behavior in the concentration range was found to be 0.02–1.0 µM, with LOD values of 0.003 nM in PBS 7.0 and 0.065 nM in serum samples. The electrochemical mechanism of NEL at the bare and modified GCEs were revealed as diffusion-controlled and adsorption-controlled mechanism processes, respectively. The linear calibration curves at both the bare and modified GCEs were noticed for increasing NEL concentrations, as constructed from the DPV measurements. Applications of the Bi₂O₃NPs-AgNPs-ErGO/GCE for NEL detection in pharmaceutical dosage form and human serum sample showed well-accepted recovery results of 98–99 %. The effect of interfering agents was checked on the selectivity of the developed method, and the modified electrode was found to be selective toward NEL in the presence of these interfering agents.