Abstract
The food safety issues related to the pesticide residues in agricultural produce have increased the demand for instruments that can rapidly, sensitively, and selectively detect pesticide residues in food commodities. This idea served as the impetus for the development of protocols for the detection and quantification of various insecticide residues using GST-based biosensor probes. We demonstrated the effectiveness of GST-based biosensor and compared with analytical methods such as GC-MS/LC-MS for application in detection of multi-residue insecticides viz., synthetic pyrethroid and neonicotinoid in bitter gourd samples. Spectrophotometric analysis was confirmed from Michaelis-Menten constant (Km) and maximum velocity (Vmax) in the range 0.00178–0.00767 M and 0.01519–0.05249 mM/s for six different insecticides. Further, GST-based biosensor for the detection of various insecticides showed good linear curve (R2 > 0.98) in the range from 0.01 to 0.5 mg kg− 1 with LOD and LOQ calculated in 0.01 and 0.05 mg kg− 1. Method validation parameters namely linearity, recovery inhibition were calculated 1.83–65.10%, accuracy (71–100%) and precision (RSD < 6.0%), respectively. Among the 20 farmgate and market samples subjected to different techniques, imidacloprid residues were detected in four bitter gourd samples ranging from 0.042 to 0.099 mg kg− 1 in LC-MS and 0.050–0.10 mg kg− 1 for three samples in GST-based biosensor techniques.