Cuartero_2012_Anal.Biochem_421_208

An acetylcholine-selective electrode based on a plasticized polymeric membrane has been developed. The electrode exhibited good selectivity for acetylcholine (ACh) over choline and some common ions, low drift, and a fast response to ACh. The response was linear over an ACh concentration range of 1x10(-6) to 1x10(-3) M with a slope of 59.1+/-0.1 and a detection limit of 1.5x10(-7)+/-1.2x10(-8) M. The electrode was used to monitor enzymatic ACh hydrolysis catalyzed by acetylcholinesterase (AChE) at different substrate and enzyme concentrations. A kinetic data analysis permitted the determination of the Michaelis-Menten constant of the enzymatic hydrolysis and AChE activity in the range of 2x10(-5) to 3.8x10(-1)U ml(-1).