A Highly Efficient Nano-Cluster Artificial Peroxidase and Its Direct Electrochemistry on a Nano Complex Modified Glassy Carbon Electrode

• Published in: Analytical Sciences Vol. 28; no. 7; pp. 711 - 716
• Main Authors: YANG, Wei-Yun, GAO, Yun-Fei, XIAO, Bao-Lin, ZHAO, Ying-Xue, MOOSAVI-MOVAHEDI, Zainab, WANG, Wei, MOOSAVI-MOVAHEDI, Ali Akbar, HUANG, Kun, HONG, Jun, GHOURCHIAN, Hedayatollah
• Format: Journal Article
• Language: English
• Published: Singapore The Japan Society for Analytical Chemistry 2012; Springer Nature Singapore; Nature Publishing Group
• Subjects: Analytical Chemistry; Animals; Biomimetic Materials - chemistry; Biomimetic Materials - metabolism; Biosensing Techniques; Carbon; Catalysts; Chemistry; Constants; Cytochromes c - metabolism; Electrochemistry; Electrochemistry - instrumentation; Electrochemistry - methods; Electrodes; Fluorocarbon Polymers - chemistry; Glass - chemistry; Glassy carbon; Gold - chemistry; Hydrogen Peroxide - analysis; Hydrogen-Ion Concentration; Kinetics; Limit of Detection; Membranes, Artificial; Metal Nanoparticles - chemistry; Nanocomposites; Nanomaterials; Nanostructure; Nanostructures - chemistry; Nanotubes, Carbon - chemistry; Peroxidase; Peroxidase - metabolism; Spectrometry
• ISSN: 0910-6340; 1348-2246; 1348-2246
• DOI: 10.2116/analsci.28.711

A nano-cluster with highly efficient peroxide activity was constructed based on nafion (NF) and cytochrome c (Cyt c). UV-Vis spectrometry and transmission electron microscopy (TEM) methods were utilized for characterization of the nano-structured enzyme or artificial peroxidase (AP). The nano-cluster was composed of a Chain-Ball structure, with an average ball size of about 40 nm. The Michaelis–Menten (Km) and catalytic rate (kcat) constants of the AP were determined to be 2.5 ± 0.4 μM and 0.069 ± 0.001 s−1, respectively, in 50 mM PBS at pH 7.0. The catalytic efficiency of the AP was evaluated to be 0.028 ± 0.005 μM−1 s−1, which was 39 ± 5% as efficient as the native horseradish peroxidase (HRP). The AP was also immobilized on a functional multi-wall carbon nanotube (MWNCTs)-gold colloid nanoparticles (AuNPs) nano-complex modified glassy carbon (GC) electrode. The cyclic voltammetry of AP on the nano complex modified GC electrode showed a pair of well-defined redox peaks with a formal potential (E°′) of –45 ± 2 mV (vs. Ag/AgCl) at a scan rate of 0.05 V/s. The heterogeneous electron transfer rate constant (ks) was evaluated to be 0.65 s−1. The surface concentration of electroactive AP on GC electrode (Γ) was 7 × 10−10 mol cm−2. The apparent Michaelis–Menten constant (Kmapp) was 0.23 nM.