Green light-responsive photoelectrochemical sensing nanoplatform based on copper cobaltite nanorods for ultrasensitive detection of furazolidone antibiotic residue in food samples

Abstract

In this research, the preparation of copper cobaltite (CuCo₂O₄) nanorods and its potential application in photoelectrochemical sensing platform towards ultrasensitive detection of furazolidone are reported. X-ray diffraction, Raman spectra, scanning electron microscopy, and UV–visible spectroscopy have been performed to confirm the formation, morphology, phase composition, and optical properties of CuCo₂O₄ synthesized by a microwave-assisted hydrothermal method. The electrochemical characteristic parameters were calculated via electrochemical impedance spectroscopy, cyclic voltammetry, differential pulse voltammetry, and chronoamperometry techniques in the absence and presence of laser light irradiation. The CuCo₂O₄-based photoelectrochemical sensing platform with laser light irradiation exhibited outstanding electrochemical performance compared to without laser light irradiation with sensitivity for furazolidone detection of 1.11 μA μM⁻¹ cm⁻² within the linear ranges of 0.25 to 200 μM, and detection limit of 0.03 μM, due to CuCo₂O₄ nanorods having a narrow energy gap, a low recombination ratio of electron–hole pairs, and multiple valence states (Co²⁺/Co³⁺ and Cu²⁺/Cu³⁺) structure. In addition, the proposed CuCo₂O₄-based photoelectrochemical sensor with light assistance showed good repeatability, anti-interfering capability, long-term stability, and real applicability in honey and milk samples.