ABSTRACT
A novel cobalt-tetraphenylporphyrin/reduced graphene oxide (CoTPP/RGO) nanocomposite was prepared by a π-π stacking interaction and characterized by ultraviolet-visible absorption spectroscopy (UV-vis), Fourier transform infrared spectroscopy (FTIR) and electrochemical impedance spectroscopy (EIS). The CoTPP/RGO nanocomposite exhibited high electrocatalytic activity both for oxidation and reduction of H2O2. The current response was linear to H2O2 concentration with the concentration range from 1.0×10(-7) to 2.4×10(-3)molL(-1) (R=0.998) at the reductive potential of -0.20V and from 1.0×10(-7) to 4.6×10(-4)molL(-1) (R=0.996) at the oxidative potential of +0.50V. The H2O2 biosensor showed good anti-interfering ability towards oxidative interferences at the oxidative potential of +0.50V and good anti-interfering ability towards reductive interferences at the reductive potential of -0.20V.
Subject(s)
Biosensing Techniques , Cobalt/chemistry , Graphite/chemistry , Hydrogen Peroxide/analysis , Nanocomposites/chemistry , Porphyrins/chemistry , Dielectric Spectroscopy , Electrochemical Techniques , Electrodes , Oxidation-Reduction , Oxides/chemistryABSTRACT
A novel glucose biosensor was constructed by using ferrocene-carbonyl-beta-cyclodextrin (FcCD) inclusive complex as electron-transfer mediator and carbon nanotubes (CNTs) as electron-transfer promoter. FcCD inclusive complex and glucose oxidase (GOx) were covalently bonded to CNTs by poly-l-lysine (PLL) to fabricate a glucose biosensor. The electrocatalytic oxidation of glucose at the biosensor occurred at low potential below 200 mV, avoiding the interference of the main interfering substances in real samples containing a 5-times higher concentration of l-cysteine, ascorbic acid, and uric acid. The biosensor showed fast response for glucose. A broad linear range of glucose concentration from 1.0 x 10(-5) to 2.90 x 10(-3) M was obtained and the detection limit was 2.2 x 10(-6) M.
