Immobilization of rat brain acetylcholinesterase on ZnS and poly(indole-5-carboxylic acid) modified Au electrode for detection of organophosphorus insecticides
2011; Elsevier BV; Volume: 29; Issue: 1 Linguagem: Inglês
10.1016/j.bios.2011.07.070
ISSN1873-4235
AutoresNidhi Chauhan, Jagriti Narang, C.S. Pundir,
Tópico(s)Cholinesterase and Neurodegenerative Diseases
ResumoA novel, highly sensitive amperometric biosensor for detection of organophosphorus (OP) compounds has been constructed, based on rat brain acetylcholinesterase (AChE) immobilized onto nanocomposite of ZnS-nanoparticles (ZnSNPs) and poly(indole-5-carboxylic acid) electrodeposited on Au electrode. In the presence of acetylthiocholine chloride (ATCl) as a substrate, ZnSNPs promoted electron transfer reactions at a lower potential and catalyzed electrochemical oxidation of enzymatically formed thiocholine, thus increasing detection sensitivity. Under optimum conditions (phosphate buffer, pH 7.5 and 30 °C), the inhibition of AChE by malathion and chlorpyrifos was proportional to their concentrations in the range, 0.1–50 nM and 1.5–40 nM, respectively. The biosensor determined malathion and chlorpyrifos in spiked tap water samples with a acceptable accuracy (95–100%). The enzyme electrode had long-storage stability (50% retention of initial activity within 2 months, when stored at 4 °C).
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