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

Abstract

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.

Role of Chlorella sp. and rhamnolipid 90 in maintaining homeostasis in soil contaminated with bisphenol A

“…4 Coefficients of impact (IF bR ) of rhamnolipid 90 for enzymes activity in soil contaminated with BPA-PCA method (for abbreviations, see Fig. 5) assumes the role of hydrogen peroxide and becomes the hydrogen donor (Hong et al 2012).…”

Electrochemical Study on A Heme-Histidine-Sodium Decyl Sulfate Nano Micelles Complex Artificial Peroxidase

“…At first, a GCE was prepared similar to the procedure given in previous literature [18][19]. Then, 3μL HFs (2mg/mL) was dropped on the prepared GCE.…”

“…6F). Then the number of electron (n), cathodic electron transfer coefficient (α), apparent heterogeneous electron transfer rate constant (k s ) and the average surface concentration of electroactive materials (MAP) on the surface of GCE (Г) could be concluded to be 1, 0.4, 1.96s -1 and 9.10×10 -9 mol/cm 2 , respectively [19][20][21][22][23]. Moreover, the size of MAP nano micelle was 3.45 nm (Scheme 1), then the theoretical concentration of one layer MAP could be calculated to be 1.40×10 -11 mol/cm 2 [12].…”

“…The detection limit was 32μmol/L. Then, according to the electrochemical version of the Linewearver-Burk Equation [19][20][21][22][23][24] and Fig. 10D, Figure 10D.…”

Carbon-Based Electrode Application for Determination and Differentiation of Chromium Ion Species Using Voltammetric Method

“…There have been several sensitive methods used for Cr(III) and Cr (VI) determination including atomic absorption spectrophotometry (AAS) [4,5], plasma mass spectroscopy [6], spectrofluorimetry [7], chemiluminescence [8], spectrophotometry [9], and electrochemical methods [10][11][12]. Determination of chromium ions using voltammetric method is evolving along with the requirements to accurately measure the ionic species [13][14][15][16][17][18].…”