A ternary nanocomposite based on nickel(iii) oxide@f-CNF/rGO for efficient electrochemical detection of an antipsychotic drug (Klonopin) in biological samples

Abstract

In this study, we developed a Ni₂O₃@f-CNF/rGO composite for the sensitive and selective electrochemical detection of Klonopin (KNP) via a simple ultrasonic method. Scanning electron microscope (SEM), high-resolution transmission electron microscopy (HR-TEM), energy-dispersive X-ray spectroscopy (EDS), X-ray powder diffraction (XRD), and Raman spectroscopy results demonstrated the successful formation of the Ni₂O₃@f-CNF/rGO composite. The electrochemical impedance spectroscopy (EIS) analysis of the Ni₂O₃@f-CNF/rGO-modified screen-printed carbon electrode (Ni₂O₃@f-CNF/rGO/SPCE) revealed a minimized charge transfer resistance (R_ct) than those for Ni₂O₃, f-CNF/rGO, and bare SPCE. In the electrochemical experiments, Ni₂O₃@f-CNF/rGO-modified SPCE exhibits superior performance towards the electrochemical detection of KNP, which provides an ultra-low detection limit of 2.8 nM in a wide concentration range of 0.08–1070.94 μM with a sensitivity of 12.02 μA μM⁻¹ cm² using the amperometric i–t method. Moreover, the practical feasibility of Ni₂O₃@f-CNF/rGO was assessed for the electrochemical determination of KNP in the human blood serum and urine samples and the result indicated appreciable recovery of KNP.