a-Cyclodextrin functionalized silver nanoparticles as colorimetric sensor for micro extraction and trace level detection of chlorpyrifos pesticide in fruits and vegetables

We report a novel UV-Vis spectrophotometry combined with micro Soxhlet extraction method for the detection of CPS pesticide in fruits and vegetables based on alpha-cyclodextrin capped silver nanoparticles (AgNPs/alpha-CD). Recently, CPS pesticide has been used as a disinfectant in post-harvesting agriculture to prevent or inhibition of recent outbreaks (COVID-19) with pathogens contamination resulting in an increased concentration of pesticides in the environment. Therefore, we developed an AgNPs/alpha-CD as a chemical sensor for the detection of CPS loaded on agricultural products. The sensing mechanism for the detection of CPS pesticide is based on the change in color of the AgNPs/alpha-CD from yellow to red followed by the redshift of the LSPR absorption band (410/570 nm) in the UV-Vis region after the addition of the analyte into the NPs solution. The changes of color and LSPR band shifting of AgNPs are observed only in CPS pesticides due to the H-bonding and non-covalent interactions of oxygen moieties with AgNPs/alpha-CD. Limit of detection (LOD) and limit of quantification (LOQ) in the region of 4.0 and 13.0 ngmL(-1) have been achieved for CPS pesticide using AgNPs/alpha-CD, respectively. These data establish the potential for this sensor for the use CPS pesticide analysis at trace levels.