Development of Dot-ELISA Technique for Detection of Chlorpyriphos Pesticide and Feasibility of its Application to Field Samples

The present study was undertaken to develop an immunoassay technique - Dot ELISA. This technique utilized nitrocellulose membrane for chlorpyriphos detection in field samples through blot appearance on it. Present study has been focused on detection of chlorpyrifos pesticide in field sprayed samples (wheat leaves, cabbage and orange) resulted in limit of detection LOD value of 75-125g/ml through Dot ELISA. Results obtained from this study showed expected values with specific sensitivity, specificity, accuracy and K value greater than 0.81 using kappa statistics. These studies were further extended for comparision with Gas Chromatography (GC) and indirect plate ELISA for which LOD values were found to be of 0.1 ng/ml and 75 ng/ml with 81-94 % recovery in each case respectively. So studies revealed that Dot ELISA has almost comparative value to indirect plate ELISA in concern to its LOD and % recovery. These comparative studies of all the three methods used i. e. GC, plate ELISA and Dot ELISA revealed about capability for pesticide residue detection with different level of sensitivity and detection limit. Results also supported that Dot ELISA can be consider an important tool for detection of chlorpyrifos residue even at field level which is not feasible with GC, and indirect plate ELISA.