Inhibition of the Acetycholine Esterase-Stimulated Growth of Au Nanoparticles:  Nanotechnology-Based Sensing of Nerve Gases

Abstract

The acetylcholine esterase, AChE, mediated hydrolysis of acetylthiocholine (1) yields a reducing agent thiocholine (2) that stimulates the catalytic enlargement of Au NP seeds in the presence of AuCl(4)(-). The reductive enlargement of the Au NPs is controlled by the concentration of the substrate (1) and by the activity of the enzyme. The catalytic growth of the Au NPs is inhibited by 1,5-bis(4-allyldimethylammoniumphenyl)pentane-3-one dibromide (3) or by diethyl p-nitrophenyl phosphate (paraoxon; 4), thus enabling a colorimetric test for AChE inhibitors. The colorimetric assay was also developed on glass supports.

Pulsed galvanostatic control of a solid-contact ion-selective electrode for potentiometric biosensing of microcystin-LR

“…where [I] is the concentration of the inhibitor, C E is the concentration of the non-inhibited enzyme and C E0 is the initial concentration of the enzyme [45,46]. Eq.…”

Modified Cholinesterase Technology in the Construction of Biosensors for Organophosphorus Nerve Agents and Pesticides Detection

“…The gold nanoparticles are deposited onto a glass surface. In reaction of enzyme with substrate the blue coloring will be shown (λ = 570 nm), after adding an inhibitor the plasmon band will be reduced and the glass plate will turn pink (Pavlov et al, 2005).…”

Organophosphorous Compounds-Toxicity and Detection Approach

“…Analytical devices based on the determination of inhibition of AChE have been widely used for the detection of OP compounds (Pavlov et al, 2005;Schulze et al 2003;Tran-Minh et al 1990). The screenprinted biosensors were used for the determination of methamidophos pesticides.…”

“…Sol-gel technology provides an attractive way for the immobilization of biological entities including full cell, enzyme, protein and antibody or antigen due to the inert low temperature process (Pandey et al 2000). Recently, the nanoparticles and carbon nanotube (CNT) have received considerable attention to increase the sensitivity of the biosensor due to then high conductivity, catalytic and electrical properties (Pavlov et al, 2005). AChE was immobilized on silica sol -gel assembling gold (Au) nanoparticles for the inhibition study with OP compounds.…”