Electrochemical Determination of Activity of Acetylcholinesterase Immobilized on Magnetic Particles

Abstract

Acetylcholinesterase (AChE) is an enzyme which terminates action of neurotransmitter acetylcholine in cholinergic system. Activity of enzyme is commonly assayed by Ellman´s method which has significant disadvantages like instability of reagents. Inability to use enzyme from the mixture repeatedly is another disadvantage. Therefore, we developed process using N-(3-dimethylaminopropyl)-N′-ethylcarbodiimide hydrochloride (EDC) to immobilize AChE on the surface of magnetic particles, which enable to separate enzyme and use it repeatedly. To determinate activity of enzyme, we optimized square wave voltammetry (SWV) method where screen-printed sensor with Prussian blue (PB) modified working electrode was performed. We report limit of detection equal 8.1 μM for a tested inhibitor of AChE tacrine. Comparing to the standard Ellman´s test, the immobilized enzyme has limited sensitivity to interferences caused by organic solvents. The proposed method is readily to practical application.

Acetylcholinesterase Inhibitors Assay Using Colorimetric pH Sensitive Strips and Image Analysis by a Smartphone

“…Despite broad use, this method has some drawbacks like instability of Ellman's reagent and hemoglobin interference [ 2 , 4 , 5 ]. Furthermore, there is possibility of measuring enzyme activity electrochemically [ 6 , 7 ]. Colorimetric detection can be also based on pH measurement.…”

Electrochemical acetylcholinesterase biosensor for detection of cholinesterase inhibitors: study with eserine

“…Mediator transfers the electron to the electrode via redox reactions. Oxidation and reduction process on cyclic voltammogram are referred to solid and dashed lines in Figure 3, respectively [18,19]. Electrons on the electrode are detected by external electrical circuit (potentiostat).…”

Construction of an Acetylcholinesterase Sensor Based on Synthesized Paramagnetic Nanoparticles, a Simple Tool for Neurotoxic Compounds Assay

“…Measuring of AChE activity is important in diagnostics or serves as a tool in analytical chemistry in inhibitor determination. A commonly acknowledged method for activity determination is Ellman’s reaction but there is potential for pH or electrochemical detection [ 2 , 3 , 4 , 5 , 6 , 7 ]. There is a demand for the determination of AChE inhibitors in a wide spectrum of used compounds like Alzheimer’s disease drugs (donepezil, rivastigmine, huperzine, galantamine), pesticides (carbofuran, malaoxon, malathion), and chemical warfare agents (sarin, soman, tabun, VX) [ 8 ].…”

“…MPs have been used for many years in protein immobilization as a good platform for the attachment of proteins through free carboxyl, hydroxyl, thio, or amino groups on their surface [ 16 , 17 , 18 ]. Many protocols for enzyme immobilization on MPs have already been reported [ 4 , 19 , 20 , 21 ]. Silane-coupling reagents (like 3-aminopropyltrimethoxysilane or 3-aminopropyltriethoxysilane) are easily used for surface modification of synthetized MPs plus provide free amino groups which can be used for enzyme immobilization [ 22 , 23 , 24 ].…”