Xanthine oxidase/laponite nanoparticles immobilized on glassy carbon electrode: Direct electron transfer and multielectrocatalysis

Supramolecular immobilization of redox enzymes on cyclodextrin-coated magnetic nanoparticles for biosensing applications

“…The biosensor showed a high sensitivity of 130 mA/M and a low detection limit of 2.0 lM, which are better or comparable to other previously described in the literature [15,31,35,37]. The biosensor showed high stability under storage at 4°C in dry conditions, retaining about 96% and 73% of its initial activity after 15 days and 1 month of storage, respectively.…”

“…There was a linear relationship between the measured anodic current and xanthine concentration ranging from 5 lM to 120 lM. In comparison with previous reports, this range of linearity is wider than that reported for other biosensors based on XO immobilized on Pd-Pt/graphite electrode (1.5-70 lM) [31], Nafion/Pt electrode (2-18.5 lM) [32], Prussian Blue/polypyrrole/Au colloid/Au electrode (1.0-70 lM) [33] and double-walled carbon nanotubes/CPE (2.0-50 lM) [34], but comparable or lower than those obtained at poly-5,2 0 :5 0 ,2 00 -terthiophine-3-carboxylic acid/ Au electrode (0.5-100 lM) [35], Au colloids/polypyrrole/Pt electrode (0.4-100 lM) [36] and laponite/GCE (39 nM-21 lM) [37].…”

Disposable amperometric biosensors based on xanthine oxidase immobilized in the Prussian blue modified screen-printed three-electrode system

“…The K m ' value of SPTE-PB-XOD electrode was calculated to be 3.90 M, which is lower than the corresponding value in other papers (9.9 mM [31], 43.3 M [32], 64 M [33]). It demonstrates that the STPE could provide better affinity between enzymes and substrates than the conventional cylindrical electrode.…”

Reagentless biosensor for hydrogen peroxide based on self-assembled films of horseradish peroxidase/laponite/chitosan and the primary investigation on the inhibitory effect by sulfide

“…The direct electron transfer between HRP molecule and electrode is very difficult to achieve because of the deeply buried electro-active centers in HRP. Direct electron transfer of protein depends strongly on the immobilization procedure, the nature of the support, and the properties and the stability of the biomolecule (Freire et al, 2003;Shan et al, 2009a). The self-assembly owns unprecedented flexibility to tailor interfacial properties and presents biologically relevant groups, which makes it well-suited for control of biomolecular density and orientation at the solid-liquid interface to obtain better reproducibility and higher efficiency .…”

“…It is significantly smaller than naturally occurring clay. Thanks to the distinguished interfacial properties, this attractive material has been successfully used to construct the biosensors (Shi et al, 2008;Fan et al, 2007;Shan et al, 2002Shan et al, , 2003Mousty et al, 2001) and realize the direct electrochemistry of the enzymes such as xanthine oxidase (Shan et al, 2009a), glucose oxidase (Shan et al, 2009b) and hemoglobin . Chit is positively charged in aqueous acidic media (pH < 6.5), negatively charged laponite can be anchored on the Chit-modified electrode via electrostatic attraction.…”