The integration of Mn and Co redox couples endowed MnCo(2)O(4)-modified electrochemical sensing platform for ultrasensitive detection of Carbendazim residue in fruit and vegetable samples.

This study reports the carbendazim (CBZ) detecting capability of spinel cobaltite MnCoO (MCO) synthesized via a microwave-assisted hydrothermal approach. The MCO-modified screen-printed electrode (MCO/SPE) exhibited excellent electrocatalytic activity toward CBZ oxidation. As a result, the proposed sensor enables sensitive CBZ detection over two distinct linear ranges (0.05-5 μM and 25-500 μM), with a low detection limit of 0.02 μM and a high sensitivity of 6.46 μA μM cm. The enhanced sensing performance is attributed to the synergistic redox activity of Co/Co and Mn/Mn couples, which enhance both electrical conductivity and catalytic activity, together with the nanorod morphology that promotes efficient diffusion of CBZ molecules and electrolyte species. The applicability of the MCO/SPE was further validated through effective CBZ detection in fruit and vegetable samples as compared with the liquid chromatography-tandem mass spectrometry (LC-MS/MS) method, showing strong potential for food safety monitoring.