Synergistic Effects of plasmonic and semiconductor nanoparticles on graphene oxide for thiodicarb pesticide detection and Detoxification

Abstract

Organic pesticides, commonly used in agriculture, present significant risks to both health and the environment. Surface-Enhanced Raman Spectroscopy (SERS) provides a highly sensitive approach for detecting trace amounts of pesticides. This study introduces the design and fabrication of highly sensitive GOAg and GOAg@ZnO nanocomposites, SERS substrates for the ultrasensitive detection and degradation of thiodicarb pesticides, enabling rapid environmental monitoring. Graphene oxide (GO) was synthesized using a modified Hummer’s method, while GOAg and GOAg@ZnO nanocomposites were prepared through chemical reduction. The materials were characterized using various techniques, including XRD (to determine crystalline structure), UV–Vis spectroscopy (for optical absorption and band gap analysis), Raman spectroscopy (to identify G, D, and 2D bands), and HRTEM (to study morphology). SERS and photocatalytic analyses were conducted to detect and degrade thiodicarb pesticides on potato peels using the nanocomposites substrates. The SERS results revealed remarkable detection limits of 10^-11 M (GOAg) and 10^-12 M (GOAg@ZnO), enabling precise identification of thiodicarb pesticides. Additionally, the GOAg and GOAg@ZnO nanocomposites demonstrated exceptional performance, with enhancement factors of 9.7 × 10⁷ and 8.6 × 10⁷, detection limits as low as 10^-9 M on potato peels, and degradation efficiencies of 48 % (GOAg) and 84 % (GOAg@ZnO) under UV irradiation. The corresponding rate constants were 0.005 min⁻¹ and 0.144 min⁻¹, respectively. These results highlight the nanocomposites excellent stability, uniformity, sensitivity, and efficiency, showcasing their potential for the detection and degradation of thiodicarb pesticides.