Acting as a potent microtubule inhibitor, the dinitroaniline herbicide trifluralin has been used in agricultural applications as a selective, pre-emergence herbicide in various plant cultures including grain, crops, vegetables, fruits and nuts. In recent years, the compound is a subject to increasing toxicological and environmental concerns. OWLS offered a highly sensitive label free method to develop immobilized antigen-BSA conjugate based competitive immunosensor.