In-situ formed selenium-enriched CoSe2-FeSe2/N-doped MWCNT heterostructure for detection of butralin in agricultural food commodities.

The development of reliable electrochemical sensors is essential for monitoring hazardous agrochemicals that threaten food safety. Butralin (BTN), a carcinogenic dinitroaniline herbicide, can migrate from soil to edible crops, raising significant health concerns. In this work, a sensitive voltammetric sensor was developed using an in-situ formed, selenium-enriched CoSe2@FeSe2 (CFS) heterostructure integrated with N-doped multi-walled carbon nanotubes (N-MWCNTs). The CFS heterostructure promotes efficient charge transfer and enhances electrocatalytic activity, while N-doped MWCNTs improve conductivity and provide abundant active sites. The resulting composite (CFS/N-MWCNT) exhibited excellent analytical performance, with a low detection limit (0.013 μM), high sensitivity (3.751 μA μM-1 cm-2), and good repeatability. This sensor was successfully applied to determine BTN in real agricultural food samples, including vegetables and legumes, with satisfactory recovery. These results demonstrate the potential of the proposed platform for practical determination of BTN in agricultural food matrices.