Garnering sensitivity: A horseradish peroxidase and MoS2@black phosphorene based electrochemical biosensor for glyphosate detection

Glyphosate (GLY) is one of the most widely used herbicides, and the presence of its residues in food samples poses a threat to human health. Developing a monitoring system could help address food safety concerns. This study presents an innovative electrochemical sensing platform to detect GLY, which employs molybdenum disulfide (MoS 2 ) and black phosphorene (BP) nanocomposites (MoS 2 @BP) with horseradish peroxidase (HRP) for the working electrode modification. The MoS 2 @BP nanocomposite is synthesized using a hydrothermal method, and its characteristics are investigated through different methods including scanning electron microscopy, X-ray photoelectron spectroscopy, and X-ray diffraction methods. The presence of BP enhances electrical conductivity and increases specific surface area, while MoS 2 improves the electrochemical properties of the composites and provides a protective effect on BP. The modification of MoS₂@BP on the electrode surface helps to accelerate the direct electron transfer of HRP with enhanced electrochemical responses. Furthermore, the incorporation of amino acid residues from HRP significantly enhances the recognition of GLY, thereby improving the selectivity and sensitivity of this electrochemical sensor. The sensor operates effectively within a linear concentration range from 0.118 nmol/L to 20.65 μmol/L, with a low detection limit of 0.0393 nmol/L (3σ). Furthermore, the sensor is successfully applied to detect GLY in real cornmeal samples with satisfactory results, demonstrating its potential applications in food safety monitoring.