title: Horseradish peroxidase immobilization on carbon nanodots/CoFe layered double hydroxides: direct electrochemistry and hydrogen peroxide sensing.
abstract: Carbon nanodots and CoFe layered double hydroxide composites (C-Dots/LDHs) were prepared via simply mixing C-Dots and CoFe-LDHs. The as-prepared composites were used for the immobilization of horseradish peroxidase (HRP) on the glass carbon (GC) electrode. The electrochemical behavior of the HRP/C-Dots/LDHs/GC electrode and its application as a H2O2 biosensor were investigated. The results indicated that HRP immobilized by C-Dots/LDHs retained the activity of enzyme and displayed quasi-reversible redox behavior and fast electron transfer with an electron transfer rate constant ks of 8.46 s(-1). Under optimum experimental conditions, the HRP/C-Dots/LDHs/GC electrode displayed good electrocatalytic reduction activity and excellent analytic performance toward H2O2. The H2O2 biosensor showed a linear range of 0.1-23.1 μM (R(2) = 0.9942) with a calculated detection limit of 0.04 μM (S/N = 3). In addition, the biosensor exhibited high sensitivity, good selectivity, acceptable reproducibility and stability. The superior properties of this biosensor are attributed to the synergistic effect of HRP, C-Dots and CoFe-LDHs, which has been proved by investigating their electrochemical response to H2O2. Thus the C-Dots and LDHs composites provide a promising platform for the immobilization of redox enzymes and construction of sensitive biosensors.
authors.affiliation: Key Laboratory of Chemo-Biosensing, Anhui Province, College of Chemistry and Materials Science, Anhui Normal University, Wuhu 241000, PR China. Electronic address: wyinl@mail.ustc.edu.cn.
authors.forename: Yinling
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Key Laboratory of Chemo-Biosensing, Anhui Province, College of Chemistry and Materials Science, Anhui Normal University, Wuhu 241000, PR China.
authors.forename: Zhangcui
authors.initials: Z
authors.lastname: Wang
authors.affiliation: Key Laboratory of Chemo-Biosensing, Anhui Province, College of Chemistry and Materials Science, Anhui Normal University, Wuhu 241000, PR China.
authors.forename: Yeping
authors.initials: Y
authors.lastname: Rui
authors.affiliation: Key Laboratory of Chemo-Biosensing, Anhui Province, College of Chemistry and Materials Science, Anhui Normal University, Wuhu 241000, PR China. Electronic address: limaoguo@mail.ahnu.edu.cn.
authors.forename: Maoguo
authors.initials: M
authors.lastname: Li
mesh_terms: D015374:Biosensing Techniques / Q000379:methods*; D002244:Carbon / Q000737:chemistry*; D003035:Cobalt / Q000737:chemistry*; D055664:Electrochemical Techniques / Q000379:methods; D004800:Enzymes, Immobilized / Q000737:chemistry* / Q000378:metabolism; D006735:Horseradish Peroxidase / Q000737:chemistry* / Q000378:metabolism; D006861:Hydrogen Peroxide / Q000032:analysis* / Q000378:metabolism; D006878:Hydroxides / Q000737:chemistry; D007501:Iron / Q000737:chemistry*; D057230:Limit of Detection; D049329:Nanostructures / Q000737:chemistry / Q000648:ultrastructure; D015203:Reproducibility of Results
chemical_list: D004800:Enzymes, Immobilized; D006878:Hydroxides; D003035:Cobalt; D002244:Carbon; D006861:Hydrogen Peroxide; D007501:Iron; D006735:Horseradish Peroxidase
keywords: Carbon nanodots; CoFe layered double hydroxides; Electrocatalysis; Horseradish peroxidase; Hydrogen peroxide