title: Electroactive layer-by-layer films of heme protein-coated polystyrene latex beads with poly(styrene sulfonate).
abstract: In this work, a novel two-step construction strategy for protein layer-by-layer assembly films was proposed. In the first step, positively charged hemoglobin (Hb) or myoglobin (Mb) at pH 5.0 was adsorbed on the negatively charged surface of 500 nm diameter-sized polystyrene (PS) latex beads, forming core-shell structured PS-protein particles. In the next step, the PS-protein particles were further assembled layer by layer with oppositely charged poly(styrene sulfonate)(PSS) on various solid surfaces under suitable conditions. Cyclic voltammetry (CV), quartz crystal microbalance (QCM), and UV-vis spectroscopy were used to monitor the growth of {(PS-protein)/PSS}(n) films. The stable {(PS-protein)/PSS}(n) films modified on pyrolytic graphite (PG) electrodes demonstrated good electroactivity in protein-free buffer, which was originated from protein heme Fe(III)/Fe(II) redox couples, and the electroactivity extended to six (PS-protein)/PSS bilayers. UV-vis spectroscopy showed that Hb and Mb in the films retained their near-native structure in the medium pH range. {(PS-protein)/PSS}(n) films catalyzed electrochemical reduction of oxygen, hydrogen peroxide, trichloroacetic acid (TCA) and nitrite with a significant lowering of overpotential, and displayed better catalytic activity than corresponding cast PS-protein films.
authors.affiliation: Department of Chemistry, Beijing Normal University, Beijing 100875, China.
authors.forename: Hong
authors.initials: H
authors.lastname: Sun
authors.forename: Naifei
authors.initials: N
authors.lastname: Hu
mesh_terms: D000818:Animals; D004563:Electrochemistry / Q000295:instrumentation / Q000379:methods; D006454:Hemoglobins; D007840:Latex; D008839:Microelectrodes; D008863:Microspheres; D009211:Myoglobin; D011137:Polystyrenes; D011506:Proteins
chemical_list: D006454:Hemoglobins; D007840:Latex; D009211:Myoglobin; D011137:Polystyrenes; D011506:Proteins; C003321:polystyrene sulfonic acid