Enzymatic flow injection method for rapid determination of choline in urine with electrochemiluminescence detection

Abstract

In order to determine trace choline in human urine, a flow injection analysis (FIA) system has been developed by coupling of an enzyme reactor with an electrochemiluminescence (ECL) detector. The enzyme reactor is prepared by covalently immobilizing of choline oxidase (ChOx) onto the aminopropyl-controlled pore glass beads, which are then carefully packed into a micro column. The enzyme reactor catalyzes the production of hydrogen peroxide that is in direct proportion to the concentration of choline. In this study, the enzymatically produced hydrogen peroxide was detected by an ECL detector positioned at the down stream of enzyme reactor based on the luminol/H 2 O 2 ECL system. Under the optimized condition, the enzymatic FIA/ECL provided high sensitivity for the determination of choline with the detection limit as low as 0.05 M (absolute detection limit was at sub pmol level). The method was successfully applied in the determination of choline in the samples of human urine, and the analytical results were in good agreement with those obtained by using the microbore HPLC with immobilized enzyme reactor-electrochemical detection system.

Quantification of acetylcholine, choline, betaine, and dimethylglycine in human plasma and urine using stable-isotope dilution ultra performance liquid chromatography–tandem mass spectrometry

“…Additionally, differences in choline metabolites according to gender are consistent with earlier studies [7,[30][31][32]. The urine choline concentrations found in our study [median (10-90th) 22.41 (10.19-49.69) mol/L] are in agreement with earlier results [33,34]. Urinary excretion of ACh correlated stronger to plasma choline in females than in males suggesting that plasma choline might be related to a higher production of ACh.…”

Applications of Electrochemiluminescence

“…This method employs the coupling of an enzyme reactor with an ECL detector. This enzymatic FIA/ECL provided high sensitivity for the determination of choline with the detection limit as low as 0.05 lM [97].…”

Enhanced Electrocatalytic Detection of Choline Based on CNTs and Metal Oxide Nanomaterials

“…Choline modulates the integrity of deoxyribonucleic acid (DNA) and is required for neural coordination in the central nervous system (CNS), being a precursor to acetylcholine (ACh). ACh aids the signaling of the cell membrane, transport of lipoproteins, spinal cord structure, cognitive functioning, muscle control and metabolism of methyl groups, particularly homocysteine [1,7,8,10,11,[14][15][16][17][18][19][20][21][22][23][24]. At a periconceptional stage, choline prevents neural tube defects (congenital disabilities of the brain, spinal cord or spine).…”