A smartphone-integrated optosensing platform based on red-emission carbon dots for real-time detection of pyrethroids

This report described the development of an optosensing platform based on red-emission carbon dots (RCDs) integrated with a smartphone application that, together, can detect pyrethroids in real time. Based on the high stability and selectivity of molecular imprinting technology, RCDs-based optosensing imprinted polymers was obtained by using a one-pot inverse microemulsion surface imprinting method. Lambda-cyhalothrin (LC), which is a pyrethroid pesticide, can interact with the widely distributed –NH2 groups on the surface of the RCD-based optosensing nanomaterials to achieve fixed-point adsorption. The quantitative detection of pyrethroids in a wide concentration range (1–120 μg/L) could be achieved, and the limit of detection (LOD) was 0.89 μg/L. Furthermore, a portable UV light box combined with a smartphone was used to convert the change in fluorescence of the RCDs-based optosensing nanomaterials into specific values upon adding pyrethroids, and the LOD by using smartphone was 6.66 μg/L. The developed platform has numerous advantages, including low cost, simple operation, high sensitivity, and good specificity, among others, and it achieves on-site visualization and rapid detection.