title: Direct electrochemistry and electroanalysis of hemoglobin adsorbed in self-assembled films of gold nanoshells.
abstract: Gold nanoshells (GNSs), consisting of a silica core and a thin gold shell, were self-assembled on the surface of 3-aminopropyltrimethoxysilane (APTES) modified indium tin oxide (ITO) electrode. The resulting novel GNSs-coated ITO (GNSs/APTES/ITO) electrode could provide a biocompatible surface for the adsorption of hemoglobin (Hb). The UV-visible (UV-vis) spectra indicated that Hb adsorbed on the GNSs interface retained the native structure. Electrochemical impedance spectra and cyclic voltammetric techniques were employed to evaluate the electrochemical behaviors of Hb, the results demonstrated that GNSs could act as electron tunnels to facilitate electron transfer between Hb and the electrode. Based on the activity of Hb adsorbed on the GNSs/APTES/ITO electrode toward the reduction of hydrogen peroxide, a mediator-free H(2)O(2) biosensor was constructed, which showed a broad linear range from 5muM to 1mM with a detection limit of 3.4muM (S/N=3). The apparent Michaelis-Menten constant was calculated to be 180muM, suggesting a high affinity.
authors.affiliation: State Key Laboratory of Bioelectronics, Department of Biological Science and Medical Engineering, Southeast University, Nanjing 210096, PR China; School of Chemistry and Chemical Engineering, Southeast University, Nanjing 210096, PR China.
authors.forename: Yi
authors.initials: Y
authors.lastname: Wang
authors.forename: Weiping
authors.initials: W
authors.lastname: Qian
authors.forename: Yong
authors.initials: Y
authors.lastname: Tan
authors.forename: Shaohua
authors.initials: S
authors.lastname: Ding
authors.forename: Haiqian
authors.initials: H
authors.lastname: Zhang