Microtiter plate enzyme linked immunoassay (ELISA) experiments in competitive format were performed utilizing polyclonal antibody for establishing a detection system for organophosphate pesticides. IC50 value of and limit of detection (LOD) value was determined by standard inhibition curve and value obtained were 0.05 μgmL(-1) and 0.001 μgmL(-1), respectively. Specificity of antibody was investigated with different organophosphate pesticides. Immunochromatographic assay (ICA) experiments were also designed in competitive format by making use of immunochromatographic strip which was assembly of three main components: conjugate pad, membrane and adsorbent pad. Membrane was coated with hapten-OVA conjugate (test line) and antirabbit IgG (control line). ICA experiments were performed by employing gold-labeled antibody as a detector reagent which was applied over conjugate pad. Visual detection limit obtained from ICA was 0.5 μgmL(-1). Major advantage of strip assay was rapid result, i.e., less than 10 min. which makes it suitable for onsite applications.
Keywords: ELISA; gold-labeled antibody; immunochromatographic assay; organophosphate pesticides; standard inhibition curve.