Abstract

Atrazine, a pesticide is a xenobiotic compound known to be a putative endocrine disruptor that may cause serious health risks even at very low levels. As per World Health Organization (WHO) the permissible limit of atrazine is restricted to 2 μg L-1 in drinking water and 0.02 -15 ppm (mg L-1) in food and it has been classified as Class 3a carcinogen as per IARC 2001. We report application of anti-atrazine based immune sensor for detection of atrazine using directly deposited gold nanostructures onto ITO glass slides for environmental monitoring. Non-toxic, simple and directly deposited gold nano structures (GNS-ITO) were characterized using cyclic voltammetry and UV visible absorption that showed characteristic absorption peak at ~559 nm confirming presence of 20-30 nm sized nano-structured hexagonal humps. Anti-atrazine has been covalently immobilized onto GNS-ITO and characterized using FT-IR spectroscopy, CV and SEM. Interestingly, SEM images reveals that the GNS grown on the surface are spherical and symmetrically distributed throughout the surface. Fabricated immune electrodes were used to sense atrazine through Square Wave Voltammetry and it was found to have dyanamic linear range from 50 aM - 1 nM (10.78 fg mL-1 - 215 pg mL-1) in 60 s antigen exposure time. Fabricated immune electrode was also shown to retain substantial stability till 12 weeks upon storage at 4°C in desiccated condition and showed no binding with non-specific antigens like malathion, parathion, 2-amino anthracene, albendazole etc. This system offers the potential for rapid, cost-effective immunosensing for the analysis of samples of environmental, medical and pharmaceutical significance.

Keywords: Atrazine, Immunosensor, Gold-nano-structures, Pesticides, Environmental monitoring