Physicochemical Characterization of Starch/Citrate-Capped Plasmonic Nanoparticles for Effective Quantification of Fenobucarb Pesticides in Fruits

Nanoparticles have attracted the attention of researchers, according to the optical properties exhibited, for showing a significant improvement in UV–visible sensitivity. The current research deals with fabricating colorimetric films by admixing starch with silver nanoparticles (Cit-AgNPs) to detect fenobucarb in fruits. The resulting films present a homogeneous surface with a thickness depending on the amount of Cit-AgNPs incorporated. After coating with fenobucarb, the film could displace the negatively charged Ag surfaces. It is remarkable that metal nanoparticles, endowed with specific ligands, show huge promise for developing miniaturized colorimetric assays. This implies that they can detect a great range of molecules, allowing the determination of trace-level target analytes by discernible visible color changes perceivable through the naked eye. This has been successfully realized through surface plasmon resonance localized principles and aggregation of nanoparticle self-assembly, enhancing plasmonic Ag from the original transition of yellow to dark grey-brown hue. In the proposed sensor methodology, the linear range is 0.005 to 500 µM, with corresponding values in the limit of detection and quantification at 8.86 µM and 29.53 µM, respectively. The present investigation is a paradigm of reporting facile, rapid, and low-cost approaches to determine fenobucarb in food commodities and further evaluates a novel approach to food safety. Also, in grapes, pumpkins, and passion fruit, its determination with high reproducibility and reliability is determined. This research developed a new methodological framework for better food safety analysis.