Electrochemistry of Gd2(MoO4)3-rGO nanocomposite for highly sensitive and selective detection of hazardous hydroquinone and chloramphenicol

Abstract

A novel electrochemical sensor based on Gd2(MoO4)3 (Gam) and rGO nanocomposite has been developed for sensitive and selective detection of hydroquinone (HQN) and chloramphenicol(CPC). Gam nanosheets have been prepared using a simple hydrothermal method with varying reaction temperatures. The formation of Gam has been analyzed using several analytical techniques. Electrochemical properties of Gam-150 were investigated using cyclic voltammetry (CV), linear sweep voltammetry (LSV), electrochemical impedance spectroscopy (EIS), and Mott-Schottky analysis and found enhanced by rGO incorporation. Gam@rGO loaded GCE sensor has been used for voltammetric and amperometric detection of HQN and CPC. The simultaneous CV analysis of HQN and CPC proved the capability of Gam@rGO loaded GCE to execute the simultaneous redox reactions. The voltammetric limit of detection (LOD) and linear range for HQN were found to be 0.0129 and 0.05–0.24 μM respectively with high sensitivity of 126.81 μA μM−1 cm−2. The amperometric LOD and linear range for CPC were found to be 0.0063 μM and 0.02–0.09 μM respectively with a sensitivity of 23.96 μA μM−1 cm−2. Gam@rGO loaded GCE has also been employed for real sample analysis with excellent recoveries. The long-term storage stability and reusability of Gam@rGO loaded GCE and real samples analysis validated its use for environmental and clinical sample analysis.