title: Direct electron transfer and electrocatalysis of hemoglobin in layer-by-layer films assembled with Al-MSU-S particles.
abstract: In this paper, layer-by-layer (LBL) {MSU/Hb}(n)/PDDA films assembled by alternate adsorption of positively charged hemoglobin (Hb) and negatively charged mesoporous molecular sieves of Al-MSU-S onto a glassy carbon electrode (GCE) were reported. Al-MSU-S was synthesized by the precursor of zeolite Y and ionic liquids 1-hexadecane-3-methylimidazolium bromide (CMIMB) as a template in basic medium. It exhibited larger pore diameter, pore volume and surface area. Direct electrochemical and electrocatalytic properties of Hb in these layer-by-layer films were investigated. A pair of well-defined nearly reversible cyclic voltammetric peaks was observed and the formal potential of the heme Fe(III)/Fe(II) redox couple was found to be -0.295V (vs. SCE). The influences of layer's number and the pH of the external solution to the electron transfer behavior of Hb in {MSU/Hb}(n)/PDDA films were also estimated by cyclic voltammetry and a set of optimized conditions for film fabrication was inferred. The hemoglobin in{MSU/Hb}(n)/PDDA films displayed a good electrocatalytic activity to the reduction of hydrogen peroxide, which had linear current responses from 1.0 x 10(-6) to 1.86 x 10(-4)mol/L with the detection limit of 5.0 x 10(-7)mol/L (S/N=3). The apparent Michaeli-Menten constant (K(m)(app)) was 0.368 mmol/L. Thus, this methodology shows potential application of the preparation of third-generation biosensors.
authors: Department of Chemistry, East China Normal University, Zhongshan Road (N), Shanghai 200062, PR China.
authors: Zhiyu
authors: Z
authors: Sun
authors: Youqin
authors: Y
authors: Li
authors: Tianshu
authors: T
authors: Zhou
authors: Ye
authors: Y
authors: Liu
authors: Guoyue
authors: G
authors: Shi
authors: Litong
authors: L
authors: Jin
mesh_terms: D015374:Biosensing Techniques / Q000379:methods*; D002384:Catalysis; D004566:Electrodes; D006454:Hemoglobins / Q000737:chemistry*; D006861:Hydrogen Peroxide; D007700:Kinetics; D010084:Oxidation-Reduction
chemical_list: D006454:Hemoglobins; D006861:Hydrogen Peroxide