Direct hapten coated ELISA for immunosensing of low molecular weight analytes

We report a protocol that employs direct coating of smaller hapten on microtiter ELISA plates for the detection of low molecular weight analytes such as pesticides in an immunoassay format. In this method, the polystyrene surface of microtiter plates was functionalize with amino groups using 3-aminoprpyltriethoxysilane (APTES) for the covalent linkage to small molecular hapten with carboxyl groups. The developed immunoassay format could be used as convenient quantitative tool for the sensitive and rapid screening of pesticides and other low molecular weight analytes in samples.