Abstract
Using an enzyme-linked immunosorbent assay (ELISA), a biosensor was developed to rapidly measure fungicide iprovalicarb residues in agricultural products. The biosensor was designed to include micro-pumps and solenoid valves for fluid transport, a spectrophotometer cuvette as a reaction chamber, a photodiode with a light-emitting diode for optical density measurement, and a control microcomputer to implement assay. The rate of change in optical density of the cuvette was read as final signal output. Micro-pumps were evaluated to investigate their delivery capability. The maximum error and the coefficient of variation were found to be 4.3% and 4.6%, respectively. To predict the concentration of the iprovalicarb residue in agricultural products, a linear calibration model was obtained with r-square values of 0.992 for potato and 0.985 for onion. In validation test for the samples of potatoes and onions against the high performance liquid chromatography (HPLC), very high correlation values were obtained as 0.996 and 0.993, respectively. Using the cuvette immobilized with antigen, it took 21-minutes for the biosensor to complete the measuring process of the iprovalicarb residues . The measurement assay was successfully automated with an adequate sensitivity level to measure the government limits for iprovalicarb residues.
