title: Syntheses of fully sulfonated polyaniline nano-networks and its application to the direct electrochemistry of cytochrome c.
abstract: Fully sulfonated polyaniline nano-particles, nano-fibrils and nano-networks have been achieved for the first time by electrochemical homopolymerization of orthanilic acid using a three-step electrochemical deposition procedure in a mixed solvent of acetonitrile (ACN) and water. The diameter of the uniform nano-particles is about 60 nm, and the nano-fibrils can be organized in two-dimensional (2D) or three-dimensional (3D) non-periodic networks with good electrical contact. Average distance between contacts is about 850 and 600nm for a 2D and 3D system, respectively. The details of the poly(orthanilic acid) (POA) nano-structure were examined with a field emission scanning electron microscope (SEM). The structure and properties of POA were characterized with FTIR, UV-vis and electrochemical methods. The 3D POA nano-networks coated platinum electrode gave a direct electrochemical behavior of horse heart cytochrome c (Cyt c) immobilized on this electrode surface, a pair of well-defined redox waves with formal potential (E( degrees ')) of -0.032 V (versus Ag/AgCl) was achieved. The interaction between Cyt c and POA makes the formal potential shift negatively compared to that of Cyt c in solution. Spectrophotometric and electrochemical methods were used to investigate the interaction of Cyt c with POA. The immobilized Cyt c in the nano-networks POA film maintained its activity, showing a surface-controlled electrode process with the electron transfer rate constant (k(s)) of 21s(-1) and a of 0.53, and could be used for the electrocatalytic reduction of hydrogen peroxide. The quantitative determination of Cyt c by differential pulse voltammetry (DPV) using the fully sulfonated 3D POA nano-networks film coated platinum electrode was also studied.
authors.affiliation: State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, Jilin 130022, China.
authors.forename: Lei
authors.initials: L
authors.lastname: Zhang
authors.forename: Xiue
authors.initials: X
authors.lastname: Jiang
authors.forename: Li
authors.initials: L
authors.lastname: Niu
authors.forename: Shaojun
authors.initials: S
authors.lastname: Dong
mesh_terms: D000814:Aniline Compounds / Q000737:chemistry*; D015374:Biosensing Techniques / Q000295:instrumentation* / Q000379:methods; D020099:Coated Materials, Biocompatible / Q000737:chemistry; D045304:Cytochromes c / Q000032:analysis* / Q000737:chemistry*; D004563:Electrochemistry / Q000295:instrumentation* / Q000379:methods; D004867:Equipment Design; D019544:Equipment Failure Analysis; D006861:Hydrogen Peroxide / Q000032:analysis*; D049329:Nanostructures / Q000737:chemistry*; D013457:Sulfur Compounds / Q000737:chemistry
chemical_list: D000814:Aniline Compounds; D020099:Coated Materials, Biocompatible; D013457:Sulfur Compounds; C416807:polyaniline; D045304:Cytochromes c; D006861:Hydrogen Peroxide