A novel sulfur quantum dots-based electrochemical sensor for highly sensitive and specific detection of mancozeb

Mancozeb (MCZ), a widely used fungicide in agriculture, poses environmental and health risks due to the potential contamination of organisms through crops and drinking water. Even trace amounts of MCZ can cause long-term harm, making its detection at low concentrations of critical importance. Traditional testing methods for MCZ suffer from limitations, including the need for expensive equipment, complex procedures, high costs, and unsuitability for rapid on-site detection. To address these challenges, a portable electrochemical sensor has been developed, integrating sulfur quantum dots (SQDs) modified electrodes with a smartphone interface for the detection of MCZ in aquatic environments. SQDs were prepared through alkali etching of bulk sulfur powder using a top-down approach to modify the electrode surface. The strong coordination and complexing ability of SQDs with Mn 2+ and Zn 2+ in MCZ significantly enhances the sensor’s specificity towards MCZ, leading to improved selectivity and sensitivity. Under optimal conditions, the sensor exhibits a linear dynamic range spanning from 3 µM to 1 mM and a detection limit equal to 432.7 nM. Furthermore, the sensor demonstrates high selectivity, long-term stability, and reproducibility. This technology holds significant potential for addressing environmental and health problems associated with MCZ contamination.