title: A lactate electrochemical biosensor with a titanate nanotube as direct electron transfer promoter.
abstract: Hydrogen titanate (H(2)Ti(3)O(7)) nanotubes (TNTs) have been synthesized by a one-step hydrothermal processing. Lactate oxidase (LOx) enzyme has been immobilized on the three-dimensional porous TNT network to make an electrochemical biosensor for lactate detection. Cyclic voltammetry and amperometry tests reveal that the LOx enzyme, which is supported on TNTs, maintains their substrate-specific catalytic activity. The nanotubes offer the pathway for direct electron transfer between the electrode surface and the active redox centers of LOx, which enables the biosensor to operate at a low working potential and to avoid the influence of the presence of O(2) on the amperometric current response. The biosensor exhibits a sensitivity of 0.24 µA cm(-2) mM(-1), a 90% response time of 5 s, and a linear response in the range from 0.5 to 14 mM and the redox center of enzyme obviates the need of redox mediators for electrochemical enzymatic sensors, which is attractive for the development of reagentless biosensors.
authors.affiliation: Department of Mechanical and Aerospace Engineering, WV Nano, West Virginia University, Morgantown, WV 26506-6106, USA. Key Laboratory for Exploration of Southwestern Resources and Environmental Disaster Control Engineering of Ministry of Education, College of Resources and Environmental Engineering, Chongqing University, Chongqing 400044, People's Republic of China.
authors.forename: Mingli
authors.initials: M
authors.lastname: Yang
authors.forename: Jin
authors.initials: J
authors.lastname: Wang
authors.forename: Huaqing
authors.initials: H
authors.lastname: Li
authors.forename: Jian-Guo
authors.initials: JG
authors.lastname: Zheng
authors.forename: Nianqiang
authors.initials: N
authors.lastname: Nick Wu