Nano nickel oxide modified non-enzymatic glucose sensors with enhanced sensitivity through an electrochemical process strategy at high potential

Development of fast and sensitive sensors for glucose determination is important in food industry, clinic diagnostics, biotechnology and many other areas. In these years, considerable attention has been paid to develop non-enzymatic electrodes to solve the disadvantages of the enzyme-modified electrodes, such as instability, high cost, complicated immobilization procedure and critical operating situation et al. Nano nickel oxide (NiO) modified non-enzymatic glucose sensors with enhanced sensitivity were investigated. Potential scanning nano NiO modified carbon paste electrodes up to high potential in alkaline solution greatly increases the amount of redox couple Ni(OH)(2)/NiOOH derived from NiO, and thus improves their electrochemical properties and electrocatalytical performance toward the oxidation of glucose. The nonenzymatic sensors response quickly to glucose and the response time is less than 5 s, demonstrating excellent electrocatalytical activity and assay performance. The calibration plot is linear over the wide concentration range of 1-110 mu M with a sensitivity of 43.9 nAh/mu M and a correlation coefficient of 0.998. The detection limit of the electrode was found to be 0.16 mu M at a signal-to-noise ratio of 3. The proposed non-enzymatic sensors can be used for the assay of glucose in real sample. (C) 2010 Elsevier B.V. All rights reserved.