Development of a Direct and Indirect Chemiluminescence Immunoassay for the Detection of an Organophosphorus Compound

The following study describes the development of two imunoassays for the semiquantitative determination of the organophosphorus compound methyl phosphonic acid, p-aminophenyl 1,2,2,-trimethyl-propyl diester (MATP). These assays are a direct competitive, labelled-hapten, enzyme immunoassay and a competitive enzyme immunoassay with indirectly labelled antibody, both with luminescence determination of peroxidase. A camera luminometer was used to determine final signal strength. A constant light reaction was reached using luminol (5-amino-2,3-dihydro-1,4-phalazinedione). and by adding coumaric acid as an enhancer. A five minute interval was selected as exposure time. This phototechnical system makes a semiquantitative detection of MATP possible. The detection limits for both assays were at 10 −6 mol/l MATP. With the help of a microtiter luminometer (reader) the detection limit was reduced to 5 × 10 −8 mol/l MATP, by measuring the real intensity of the chemiluminescence signal.