A sensitive nonenzymatic hydrogen peroxide sensor based on DNA-Cu2+ complex electrodeposition onto glassy carbon electrode

In this paper, DNA-Cu2+ complex was electrodeposited onto the surface of glassy carbon (GC) electrode, which fabricated a DNA-Cu2+/GC electrode sensor to detect H2O2 with nonenzyme. Cyclic voltammogram of DNA-Cu2+/CC electrode showed a pair of well-defined redox peaks for Cu2+/Cu+. Moreover, the electrodeposited DNA-Cu2+ complex exhibited excellent electrocatalytic behavior and good stability for the detection of H2O2. The effects of Cu2+ concentration, electrodeposition time and determination conditions such as pH value, applied potential on the current response of the DNA-Cu2+/GC electrode toward H2O2 were optimized to obtain the maximal sensitivity. The linear range for the detection of H2O2 is 8.0 x 10(-7) M to 4.5 x 10(-3) M with a high sensitivity of -40.25 mu A mM(-1), a low detection limit of 2.5 x 10(-7) M and a fast response time of within 4 s. In addition, the sensor has good reproducibility and long-term stability and is interference free. (C) 2008 Elsevier B.V. All rights reserved.