Molecularly imprinted plasmonic nanosensors are robust devices capable of selective target interaction, and in some cases reaction catalysis. Recent advances in control of nanoscale structure have opened the door for development of a wide range of chemosensors for environmental monitoring. The soaring rate of environmental pollution through human activities and its negative impact on the ecosystem demands an urgent interest in developing rapid and efficient techniques that can easily be deployed for in-field assessment and environmental monitoring purposes. Organophosphate pesticides (OPPs) play a significant role for agricultural use; however, they also present environmental threats to human health due to their chemical toxicity. Plasmonic sensors are thus vital analytical detection tools that have been explored for many environmental applications and OPP detection due to their excellent properties such as high sensitivity, selectivity, and rapid recognition capability. Molecularly imprinted polymers (MIPs) have also significantly been recognized as a highly efficient, low-cost, and sensitive synthetic sensing technique that has been adopted for environmental monitoring of a wide array of environmental contaminants, specifically for very small molecule detection. In this review, the general concept of MIPs and their synthesis, a summary of OPPs and environmental pollution, plasmonic sensing with MIPs, surface plasmon resonance (SPR), surface-enhanced Raman spectroscopy (SERS) MIP sensors, and nanomaterial-based sensors for environmental monitoring applications and OPP detection have been elucidated according to the recent literature. In addition, a conclusion and future perspectives section at the end summarizes the scope of molecularly imprinted plasmonic sensors for environmental applications.

It is necessary to develop a sensitive and selective analytical method for detecting organophosphate insecticides, such as malathion, for environmental protection. Herein, we have designed an innovative sensing platform that incorporates silver nanoparticles (AgNPs) into molecularly imprinted polymers (MIPs), with AgNPs synthesized via in situ silver ion reduction during the precipitation polymerization of the MIP. Integrating AgNPs into MIP allows us to leverage both the selectivity and high sensitivity of molecular imprinting technology and the enhanced surface-enhanced Raman scattering (SERS) properties of AgNPs. The sensors demonstrate a linear detection range of 0.005-5 µg/ml and a limit of detection (LOD) of 0.005 µg/ml for malathion in water solution. The sensor is tested and evaluated in spiked drinking and tap water, obtaining recovery rates ranging from 93% to 100.5%. The AgNPs@MIP SERS sensor provides a rapid, selective, and sensitive approach for malathion detection, promising to develop an analytical tool for environmental and agricultural monitoring of organophosphate compounds.