title: Electrochemical determination of NADH and ethanol based on ionic liquid-functionalized graphene.
abstract: It is firstly reported that low-potential NADH detection and biosensing for ethanol are achieved at an ionic liquid-functionalized graphene (IL-graphene) modified electrode. A substantial decrease (440 mV) in the overvoltage of the NADH oxidation was observed using IL-graphene/chitosan coating, with oxidation starting at ca. 0 V (vs. Ag|AgCl). And the NADH amperometric response at such a modified electrode is more stable (95.4% and 90% of the initial activity remaining after 10 min and 30 min at 1 mM NADH solution) than that at bare electrode (68% and 46%). Furthermore, the IL-graphene/chitosan-modified electrode exhibited a good linearity from 0.25 to 2 mM and high sensitivity of 37.43 microA mM(-1)cm(-2). The ability of IL-graphene to promote the electron transfer between NADH and the electrode exhibited a novel and promising biocompatible platform for development of dehydrogenase-based amperometric biosensors. With alcohol dehydrogenase (ADH) as a model, the ADH/IL-graphene/chitosan-modified electrode was constructed through a simple casting method. The resulting biosensor showed rapid and highly sensitive amperometric response to ethanol with a low detection limit (5 microM). Moreover, the proposed biosensor has been used to determine ethanol in real samples and the results were in good agreement with those certified by the supplier.
authors.affiliation: State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, PR China.
authors.forename: Changsheng
authors.initials: C
authors.lastname: Shan
authors.forename: Huafeng
authors.initials: H
authors.lastname: Yang
authors.forename: Dongxue
authors.initials: D
authors.lastname: Han
authors.forename: Qixian
authors.initials: Q
authors.lastname: Zhang
authors.forename: Ari
authors.initials: A
authors.lastname: Ivaska
authors.forename: Li
authors.initials: L
authors.lastname: Niu
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation*; D003217:Conductometry / Q000295:instrumentation*; D004566:Electrodes; D004867:Equipment Design; D019544:Equipment Failure Analysis; D000431:Ethanol / Q000032:analysis* / Q000737:chemistry; D006108:Graphite / Q000737:chemistry*; D052578:Ionic Liquids / Q000737:chemistry*; D009243:NAD / Q000032:analysis* / Q000737:chemistry; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D052578:Ionic Liquids; D009243:NAD; D000431:Ethanol; D006108:Graphite