title: A novel nitrite biosensor based on gold dendrites with egg white as template.
abstract: Gold dendrites (AuD) were synthesized with egg white as the soft template and a novel nitrite (NO(2)(-)) biosensor was fabricated by assembly of a myoglobin (Mb)-L-cysteamine (Cys)-AuD biological hybrid.  The results of Fourier transform infrared spectra and UV-visible spectra indicated that Mb retained its original structure in the resulting Mb-Cys-AuD.  Electrochemical investigation of the biosensor showed a pair of well-defined, quasi-reversible redox peaks with E(pa) = -0.314 V and E(pc) = -0.344 V (vs. SCE) in 0.1 M, pH 7.0 sodium phosphate buffered saline at the scan rate of 200 mV/s.  The transfer rate constant (k(s)) was 1.49 s(-1).  The Mb-Cys-AuD showed a good electrochemical catalytic response for the reduction of NO(2)(-), with the linear range from 0.5 to 400 µM and the detection limit of 0.3 µM (S/N = 3).  The apparent Michaelis-Menten constant (K(M)(app)) was estimated to be 0.2 mM.  Therefore, the assembled bio-hybrid as a novel matrix opened up a further possibility for study on the design of enzymatic biosensors with potential applications.
authors.affiliation: Institute of Analytical Science/Shaanxi Provincial Key Laboratory of Electroanalytical Chemistry, Northwest University, Xi'an, Shaanxi, P. R. China.
authors.forename: Yaping
authors.initials: Y
authors.lastname: He
authors.forename: Dawei
authors.initials: D
authors.lastname: Zhang
authors.forename: Sheying
authors.initials: S
authors.lastname: Dong
authors.forename: Jianbin
authors.initials: J
authors.lastname: Zheng
mesh_terms: D000818:Animals; D015374:Biosensing Techniques; D002417:Cattle; D002623:Chemistry Techniques, Analytical; D004529:Egg White / Q000737:chemistry; D004563:Electrochemistry / Q000379:methods*; D004566:Electrodes; D006046:Gold / Q000737:chemistry*; D007700:Kinetics; D009211:Myoglobin / Q000737:chemistry; D009573:Nitrites / Q000737:chemistry*; D010084:Oxidation-Reduction; D017550:Spectroscopy, Fourier Transform Infrared / Q000379:methods
chemical_list: D009211:Myoglobin; D009573:Nitrites; D006046:Gold