Localized Surface Plasmon Resonance sensor of Gold Nanoparticles for detection pesticides in water

This paper reports the utilization of plasmonic properties of Gold Nanoparticles (GNPs) as an optical sensor to detect pesticides in water. The pesticides with trade name of Ridomil G MZ 68 WP fungicide and Water-Dispersible Granules WG insecticide were used in this study. Spherical GNPs of the average size of ca. 31±7 nm were grown on quartz substrate using seed mediated growth. An optical sensor system was setup, comprises a tungsten lamp light source, a duplex fiber optic probe, a spectrometer and a sensor chamber. Detection of pesticides was done by comparing the Localized Surface Plasmon Resonance (LSPR) spectra of the GNPs film immersed in the deionised water and in pesticides solutions by varying the concentration of pesticides solutions from 2.5 μg/L to 2500 μg/L. The LSPR spectra of GNPs sample were very sensitive to the presence of pesticides where the spectra intensities are increases with the concentrations of the pesticides solutions.