Potentiometric thick-film sensor for the determination of the neurotransmitter acetylcholine.
A potentiometric thick-film biosensor for the determination of the neurotransmitter acetylcholine is presented. The selective membranes consist of two layers. The first is a choline- and H(+)-selective membrane made from a poly(vinyl chloride)-poly(vinyl acetate) copolymer which is plasticized with 2-nitrophenyl octyl ether. It contains 1% m/m of the ion-pair choline phosphotungstate as an electroactive compound. Both products of the enzymic cleavage, choline and H+, are detected. The second layer is placed above the first and is made from a poly(vinyl acetate)-polyethylene dispersion polymer. It is loaded with 2% m/m of acetylcholinesterase isolated from electric eel. The linear region of the response curve extends from 2 x 10(-5) to 0.01 mol dm-3 in buffer solution and undiluted horse serum. The detection limit is 5 x 10(-6) mol dm-3 and the response time is about 4 min.
Eppelsheim
C
C
Institute for Physical Chemistry, University of Munich, Germany.
Hampp
N
N
D000109:Acetylcholine / Q000032:analysis* / Q000097:blood; D001672:Biocompatible Materials; D015374:Biosensing Techniques; D006801:Humans; D008904:Miniaturization; D011145:Polyvinyls; D011199:Potentiometry / Q000379:methods; D012680:Sensitivity and Specificity
D001672:Biocompatible Materials; D011145:Polyvinyls; C003080:poly(vinyl chloride)-poly(vinyl acetate) copolymer; D000109:Acetylcholine