title: Effective Synergistic Effect of Dipeptide-Polyoxometalate-Graphene Oxide Ternary Hybrid Materials on Peroxidase-like Mimics with Enhanced Performance.
abstract: Dipeptide-polyoxometalates (POMs)-graphene oxide (GO) ternary hybrid is an excellent peroxidase-like mimic, exhibiting enhanced peroxidase-like activity compared to POMs alone. The hybrid was readily prepared through a reprecipitation method involving electrostatic encapsulation of H3PW12O40 (PW12) by cationic diphenylalanine (FF) peptide and coassembly of FF@PW12 spheres with graphene oxide (GO). Using 3,3',5,5'-tetramethylbenzidine (TMB) as the chromogenic substrate, the peroxidase-like activity of FF@PW12 was evaluated in the heterogeneous phase, and it is 13 times higher than that of pristine PW12 in the homogeneous phase. Furthermore, ternary hybrids of FF@PW12@GO containing 5 wt % GO could enhance the activity 1.7 times higher than that of FF@PW12. The noncovalent interactions of hydrogen bonding and ionic interaction between GO and POMs are speculated to result in the synergistic effect for the enhancement of peroxidase-like performance. The strong interactions between rGO and PW12 are evaluated by a four-probe Hall measurement via the van der Pauw method, and rGO is significantly p-doped by the doping effect of PW12 with lower LUMO energy than that of the energy level of rGO and also due to the electron reservoir feature of PW12. Cyclic voltammogram measurements also suggest that GO causes significant influence on the electronic structure of the reduced forms of the redox couples of PW12. The nature of the TMB catalytic reaction may originate from the generation of the hydroxyl radical ((•)OH) from the decomposition of H2O2 by ternary hybrids and the formation of peroxo species of POM. Taking advantage of the UV-vis signals of TMB being correlated to the concentration of H2O2, FF@PW12@GO can be used to detect H2O2 within the limit of detection of 0.11 μM, and the detection range is 1-75 μM. The present method indeed opens up a promising route in constructing heterogeneous peroxidase-like mimics through the use of POMs via the introduction of GO for building H2O2 sensors.
authors.affiliation: School of Life Science and Technology, Harbin Institute of Technology , 92 West Dazhi Street, Harbin, Heilongjiang 150001, P.R. China.
authors.forename: Zhuo
authors.initials: Z
authors.lastname: Ma
authors.affiliation: State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology , Harbin, Heilongjiang 150090, China.|Key Lab of Microsystem and Microstructure, Ministry of Education, Harbin Institute of Technology , No. 2 YiKuang Street, Harbin, Heilongjiang 150080, PR China.
authors.forename: Yunfeng
authors.initials: Y
authors.lastname: Qiu
authors.affiliation: Key Lab of Microsystem and Microstructure, Ministry of Education, Harbin Institute of Technology , No. 2 YiKuang Street, Harbin, Heilongjiang 150080, PR China.
authors.forename: Huihui
authors.initials: H
authors.lastname: Yang
authors.affiliation: Key Lab of Microsystem and Microstructure, Ministry of Education, Harbin Institute of Technology , No. 2 YiKuang Street, Harbin, Heilongjiang 150080, PR China.
authors.forename: Yanmin
authors.initials: Y
authors.lastname: Huang
authors.affiliation: Key Lab of Microsystem and Microstructure, Ministry of Education, Harbin Institute of Technology , No. 2 YiKuang Street, Harbin, Heilongjiang 150080, PR China.
authors.forename: Jingjing
authors.initials: J
authors.lastname: Liu
authors.affiliation: Key Lab of Microsystem and Microstructure, Ministry of Education, Harbin Institute of Technology , No. 2 YiKuang Street, Harbin, Heilongjiang 150080, PR China.
authors.forename: Yue
authors.initials: Y
authors.lastname: Lu
authors.affiliation: Department of Materials Science and Engineering, University of California , Berkeley, California 94720-1760, United States.
authors.forename: Chen
authors.initials: C
authors.lastname: Zhang
authors.affiliation: Key Lab of Microsystem and Microstructure, Ministry of Education, Harbin Institute of Technology , No. 2 YiKuang Street, Harbin, Heilongjiang 150080, PR China.
authors.forename: PingAn
authors.initials: P
authors.lastname: Hu
mesh_terms: D001560:Benzidines / Q000737:chemistry / Q000378:metabolism; D004151:Dipeptides / Q000737:chemistry*; D004357:Drug Synergism; D006108:Graphite / Q000737:chemistry*; D006861:Hydrogen Peroxide / Q000032:analysis / Q000378:metabolism; D009195:Peroxidase / Q000737:chemistry* / Q000378:metabolism; D010649:Phenylalanine / Q000031:analogs & derivatives / Q000737:chemistry; D055672:Static Electricity; D017973:Tungsten Compounds / Q000737:chemistry*; D000099294:Polyoxometalates
chemical_list: D001560:Benzidines; D004151:Dipeptides; D006108:Graphite; D006861:Hydrogen Peroxide; D009195:Peroxidase; D010649:Phenylalanine; D017973:Tungsten Compounds; C102296:polyoxometalate I; D000099294:Polyoxometalates; C026650:phenylalanylphenylalanine; C021758:3,3',5,5'-tetramethylbenzidine
keywords: diphenylalanine; graphene; peroxidase-like; polyoxometalates; synergistic effect