A novel disposable electrochemical immunosensor for phenyl urea herbicide diuron

A disposable electrochemical immunosensor has been developed for the determination of phenyl urea herbicide-diuron using a low cost laser ablated gold electrodes (LC-LAGE) fabricated on polystyrene substrate. The electrodes were electrochemically deposited with prussian blue-gold nanoparticle (PB-GNP) film, and a competitive inhibition immunoassay was performed on LC-LAGE by using a specific hapten–protein conjugate. The binding of available diuron specific antibody on conjugate coated electrode was detected using alkaline phosphatase rabbit anti-IgG antibody. The addition of 1-naphthyl phosphate substrate resulted in the production of electrochemically active product, 1-naphthol, which was monitored using square wave voltammetry technique. The assay exhibited an excellent sensitivity and specificity showing the dynamic response range between 1 ppt and 10 ppm for diuron with detection limit around 1 ppt. This study provides insight into development of a rapid and high-throughput screening of pesticides in environmental samples at a very low cost.