Fluorescent Molecularly Imprinted Polymer based on ZnO nanoparticles for the detection of triazole pesticides

The triazole class of pesticides is widely used in modern agriculture to effectively control fungal diseases in crops, herbs and spices. However, their use raises human health concerns because they can inhibit certain human enzymes and lead to food residue problems. Among the triazoles, penconazole is particularly prevalent and toxic to humans, prompting regulatory agencies to set maximum residue levels for safety1. Traditional detection methods such as high-performance liquid chromatography, while effective, are labor-intensive, costly, time-consuming and often use organic solvents that are harmful to the environment. Therefore, research into alternative detection techniques is essential for more sustainable food analysis. This study investigates the combination of fluorescence optical methods and molecularly imprinted polymers (MIPs) for the selective detection of triazole pesticides. The aim is to develop a penconazole selective MIP using a core of zinc oxide (ZnO) nanoparticles (NPs) as a fluorophore. The ZnO surface is modified with (3-aminopropyl) triethoxysilane (APTES), where the amino group interacts with the chlorine in penconazole, changing the fluorescence intensity of ZnO and thus enabling pesticide detection2. MIPs offer a promising alternative to conventional methods by providing high selectivity and reduced analysis time. The MIP in this study is synthesized using two silanes: tetraorthosilicate (TEOS) as a crosslinker and APTES as a monomer. Polymerization occurs around the ZnO NPs, modifying the oxide surface to enhance the interaction with penconazole. The result is a porous MIP with a fluorescent core, with penconazole acting as both the target analyte and the template, which is removed after synthesis. ZnO was chosen for its safety, biocompatibility, and ease of preparation and property tuning3