Subnanomolar concentrations, enzyme

Acetylcholine is another very important neurotransmitter in the central nervous system, but its detection is usually very difl cult due to its low concentration, which falls in the nanomolar or even subnanomolar range. The enzymatic approach to its determination involves the use of two enzymes, acetylcholinesterase (AChE), which produces choline, and choline oxidase (ChOX) that yields H2O2, which is amperometrically detected. Problems arise from the concomitant presence of high amounts of endogenous choline with... 

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