Amperometric determination of organophosphate pesticides using a acetylcholinesterase based biosensor made from nitrogen-doped porous carbon deposited on a boron-doped diamond electrode

TLDR: An amperometric biosensor for the determination of organophosphate pesticides (OPs) via inhibition of the enzyme acetylcholinesterase (AChE) was described in this paper.

Abstract: The authors describe an amperometric biosensor for the determination of organophosphate pesticides (OPs) via inhibition of the enzyme acetylcholinesterase (AChE). The enzyme was immobilized on nitrogen-doped porous carbon and then placed on boron-doped diamond (BDD). The Michaelis-Menten constant for immobilized AChE is 0.177 mmol L−1, indicating that AChE has a stronger enzymatic activity and affinity due to the introduction of nitrogen-doped porous carbon. The biosensor was applied to the determination of the OPs dichlorvos and fenitrothion. The efficiency of the inhibition by dichlorvos increases linearly in the 100 pg·L-1 to 10.0 μg·L-1 concentration range. The detection limit is as low as 1.50 pg·L-1. The inhibition by fenitrothion can be detected in the same concentration range, and the detection limit is 4.40 pg·L-1 (calculated for 10% inhibition). The unique sensitivity of this assay make it a most attractive tool for the detection of OPs.