Simultaneous determination of chloramphenicol and riboflavin using a calcined NiCuO-C/MWCNT composite modified electrode in various food samples.

Reliable monitoring of chloramphenicol (CAP) and riboflavin (RBF) is essential due to their widespread use and associated health risks in food and pharmaceuticals. In this study, a novel electrochemical sensor based on a calcined nickel copper oxide (NiCuO-C) and multi-walled carbon nanotube (MWCNT) composite was developed for simultaneous detection of CAP and RBF. The composite was synthesized via a hydrothermal method followed by calcination, enhancing crystallinity and electrochemical activity. Structural and morphological analyses confirmed successful integration of NiCuO and MWCNTs. Electrochemical impedance spectroscopy (EIS) revealed reduced charge transfer resistance (Rct), while cyclic voltammetry (CV) indicated increased electroactive surface area, confirming improved interfacial electron transfer kinetics. Differential pulse voltammetry (DPV) exhibited distinct redox signals with wide linear ranges (2-100 μM for CAP, 0.05-5 μM for RBF) and low detection limits (0.593 μM for CAP, 0.023 μM for RBF). Real sample analysis showed high recovery rates, confirming practical applicability.