title: Amperometric acetylcholine sensor catalyzed by nickel anode electrode.
abstract: An amperometric method was using a nickel catalytic electrode in aqueous base solution for detecting acetylcholine (ACh). A sensing mechanism was developed in which ACh was hydrolyzed in base aqueous solution to produce the acetic anion and choline. The alcohol group of choline was oxidized to the corresponding carboxylic acid by Ni(OH)2/NiOOH catalytic system. The amperometric response resulted from the current generated by ACh oxidation in response to step changes in ACh concentration. The potential window of limiting current of ACh anodic oxidation at the Ni interface was determined in NaOH electrolyte. The effect of NaOH electrolyte concentration on sensitivity was also discussed. At the optimum operating condition, the method exhibits a good linear relationship between the response current and the ACh concentration. The response time of the ACh sensing system was 10 s. Scanning electrochemical microscopy (SECM) with platinum micro-tips was used to investigate the diffusion layer thickness of Ni electrode.
authors.affiliation: Department of Chemical Engineering, National Cheng Kung University, Tainan 701, Taiwan ROC.
authors.forename: Shin
authors.initials: S
authors.lastname: Lin
authors.forename: Chung-Chiun
authors.initials: CC
authors.lastname: Liu
authors.forename: Tse-Chuan
authors.initials: TC
authors.lastname: Chou
mesh_terms: D000109:Acetylcholine / Q000032:analysis* / Q000737:chemistry*; D015374:Biosensing Techniques / Q000295:instrumentation / Q000379:methods*; D045424:Complex Mixtures / Q000032:analysis / Q000737:chemistry; D004563:Electrochemistry / Q000295:instrumentation / Q000379:methods*; D004566:Electrodes; D004867:Equipment Design; D019544:Equipment Failure Analysis; D006863:Hydrogen-Ion Concentration; D018377:Neurotransmitter Agents / Q000032:analysis / Q000737:chemistry; D009532:Nickel / Q000737:chemistry*; D010084:Oxidation-Reduction; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013499:Surface Properties
chemical_list: D045424:Complex Mixtures; D018377:Neurotransmitter Agents; D009532:Nickel; D000109:Acetylcholine