Gold nanoparticles based dipstick immuno-assay for the rapid detection of Dichlorodiphenyltrichloroethane: An organochlorine pesticide

Lisa, M. and Chouhan, R. S. and Vinayaka, A. C. and Manonmani, H. K. and Thakur, M. S. (2009) Gold nanoparticles based dipstick immuno-assay for the rapid detection of Dichlorodiphenyltrichloroethane: An organochlorine pesticide. Biosensors and Bioelectronics, In Pre. ISSN 0956-5663 (In Press)

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Abstract

Gold nanoparticles (GNPs) based dipstick competitive immuno-assay was developed to detect organochlorine pesticide such as DDT at nanogram level (ppb). GNPs of definite size were synthesized and conjugated to anti-DDT antibodies (IgY), which served as the detecting reagent. DDA-BSA conjugate (antigen) was immobilized on to nitro cellulose (NC) membrane containing strip. GNPs conjugated anti-DDT antibodies were treated with different concentrations of free DDT ranging from 0.7 ng mL-1 to 1000 ng mL-1 to form an immunocomplex. This immunocomplex solution was further reacted with DDA-BSA conjugate immobilized NC membrane containing strips by dipping the strip in the immunocomplex solution. The free GNPs conjugated anti-DDT antibodies present in the immunocomplex solution were targeted for competitive binding with immobilized DDA-BSA on NC membrane containing strip. Depending on the concentration of free DDT in the sample the binding of GNPs conjugated anti-DDT antibodies to the immobilized DDA-BSA varied and was detected by the development of red color (due to gold nanoparticles) in the detection zone of NC membrane containing strips. The intensity of color development was inversely proportional to the DDT concentration with maximum intensity at zero DDT concentration. The lowest detection limit of DDT was determined to be 27 ng mL-1 with the optimized conditions. The dipstick technique based on GNPs is suitable for the detection of several toxins in food and environmental samples and can be applied for rapid onsite testing of pesticides.

Item Type:	Article
Uncontrolled Keywords:	Nanoparticles IgY conjugates Dipstick assay Chlorinated pesticide Immunoassay Biosensor
Subjects:	600 Technology > 02 Engineering & allied operations 500 Natural Sciences and Mathematics > 04 Chemistry and Allied Sciences > 26 Pesticide Chemistry
Divisions:	Fermentation Technology and Bioengineering
Depositing User:	Food Sci. & Technol. Information Services
Date Deposited:	18 Jun 2009 10:13
Last Modified:	28 Dec 2011 10:09
URI:	http://ir.cftri.res.in/id/eprint/9049

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