Improvement of a pesticide immunosensor performance using site-directed antibody immobilisation and carbon nanotubes

The potential toxicity of pesticide residues in drinking water has meant a rigid regulation for the appearance of these pollutants. Thus, in this work, we developed a new immunosensor for atrazine detection. We focused on the optimisation of the antibody immobilisation method on sensor surface for the enhancement of the biosensor sensitivity. First, with site–directed immobilisation of rabbit anti–atrazine antibodies using goat anti–rabbit immunoglobulin, a detection limit of 0.5 ng/mL was obtained. This value is 20 times lower than the detection limit obtained with non–oriented antibodies. The second way to improve immunosensor sensitivity consisted of the addition of carbon nanotubes (CNT). As result of using these CNT, detection limit has been improved again from 0.5 ng/mL to 100 pg/mL.