@article{open1256, volume = {137}, number = {10}, month = {May}, author = {Priyanka Sharma and Vijayender Bhalla and Satish Tuteja and Manil Kukkar and C Raman Suri}, note = {Copyright of this article belongs to RSC Publishing.}, title = {Rapid extraction and quantitative detection of the herbicide diuron in surface water by a hapten-functionalized carbon nanotubes based electrochemical analyzer.}, publisher = {RSC Publishing}, year = {2012}, journal = {The Analyst}, pages = {2495--502}, keywords = {Electrodes;Antibodies/immunology; Water Pollutants}, url = {http://crdd.osdd.net/open/1256/}, abstract = {A solid phase extraction micro-cartridge containing a non-polar polystyrene absorbent matrix was coupled with an electrochemical immunoassay analyzer (EIA) and used for the ultra-sensitive detection of the phenyl urea herbicide diuron in real samples. The EIA was fabricated by using carboxylated carbon nanotubes (CNTs) functionalized with a hapten molecule (an amine functionalized diuron derivative). Screen printed electrodes (SPE) were modified with these haptenized CNTs and specific in-house generated anti diuron antibodies were used for bio-interface development. The immunodetection was realized in a competitive electrochemical immunoassay format using alkaline phosphatase labeled secondary anti-IgG antibody. The addition of 1-naphthyl phosphate substrate resulted in the production of an electrochemically active product, 1-naphthol, which was monitored by using differential pulse voltammetry (DPV). The assay exhibited excellent sensitivity and specificity having a dynamic response range of 0.01 pg mL(-1) to 10 {\ensuremath{\mu}}g mL(-1) for diuron with a limit of detection of around 0.1 pg mL(-1) (n = 3) in standard water samples. The micro-cartridge coupled hapten-CNTs modified SPE provided an effective and efficient electrochemical immunoassay for the real-time monitoring of pesticides samples with a very high degree of sensitivity.} }