Recent advances in localized surface plasmon resonance (LSPR)-based colorimetric and fluorescent nanosensors for the detection of organophosphorus pesticides

Organophosphate pesticides (OPPs) are among the most widely used pesticides, posing significant environmental and health risks due to their persistence in water, soil, and food. Developing sensitive, rapid, and cost-effective detection methods is crucial for ensuring food safety and environmental protection. Colorimetric and fluorescent optical nanosensors leveraging localized surface plasmon resonance (LSPR) in plasmonic nanoparticles, including gold, silver, and copper nanostructures, have emerged as promising tools for OPP detection due to their rapid response, high sensitivity, selectivity, and real-time monitoring capabilities. Colorimetric nanosensors leverage LSPR-induced visible color shifts resulting from nanoparticle aggregation, anti-aggregation, enzymatic inhibition, nanoparticle growth, or etching-based mechanisms. In contrast, fluorescent nanosensors utilize plasmonic interactions to enhance or quench fluorescence signals. This review critically examines recent advancements in LSPR-based nanosensors, their detection mechanisms, advantages, and limitations. Moreover, the potential integration of these sensors with emerging technologies, such as machine learning, smartphone-based imaging, and paper-based platforms, is explored to enhance their field applicability. Addressing existing challenges, including sensor stability, selectivity, and large-scale production, will be key to developing next-generation pesticide detection systems with real-world applications in food safety and environmental monitoring.