A highly efficient nano-cluster artificial peroxidase and its direct electrochemistry on a nano complex modified glassy carbon electrode.
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 (K(m)) and catalytic rate (k(cat)) 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 (k(s)) 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 (K(m)(app)) was 0.23 nM.
College of Life Science, Henan University, Kaifeng, China. hongjun@henu.edu.cn
Jun
J
Hong
Wei
W
Wang
Kun
K
Huang
Wei-Yun
WY
Yang
Ying-Xue
YX
Zhao
Bao-Lin
BL
Xiao
Yun-Fei
YF
Gao
Zainab
Z
Moosavi-Movahedi
Hedayatollah
H
Ghourchian
Ali Akbar
AA
Moosavi-Movahedi
D000818:Animals; D040761:Biomimetic Materials / Q000737:chemistry* / Q000378:metabolism; D015374:Biosensing Techniques; D045304:Cytochromes c / Q000378:metabolism; D004563:Electrochemistry / Q000295:instrumentation / Q000379:methods*; D004566:Electrodes; D005465:Fluorocarbon Polymers / Q000737:chemistry; D005898:Glass / Q000737:chemistry*; D006046:Gold / Q000737:chemistry; D006861:Hydrogen Peroxide / Q000032:analysis; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D057230:Limit of Detection; D008567:Membranes, Artificial; D053768:Metal Nanoparticles / Q000737:chemistry; D049329:Nanostructures / Q000737:chemistry*; D037742:Nanotubes, Carbon / Q000737:chemistry*; D009195:Peroxidase / Q000378:metabolism*
D005465:Fluorocarbon Polymers; D008567:Membranes, Artificial; D037742:Nanotubes, Carbon; C040402:perfluorosulfonic acid; D006046:Gold; D045304:Cytochromes c; D006861:Hydrogen Peroxide; D009195:Peroxidase