Gold nano-electrode

El-Deab MS, Okajima T, Ohsaka T. 2003. Electrochemical reduction of oxygen on gold nano-particle-electrodeposited glassy carbon electrodes. J Electrochem Soc 150 A851-A857. 

Recently, Du et al. reported an AChE electrochemical sensor based on enzyme-induced growth of gold nanoparticles (AuNPs) without the addition of any gold nano-seeds [17], They have successfully used [Fe (CN)6]3 74 as a probe to indicate the process of electron transfer across the interface and also analyze the enzyme inhibitor quantitatively. Initially, cleaned gold electrode was coated with 0.5 % (w/v) chitosan solution and AChE was later immobilized onto this chitosan modified gold electrode. CV results show that, AuNPs presence increases the peak current and decreases the peak separation. This confirms the presence of AuNPs on the chitosan modified electrode surface. However, the peak current of... 

The reconstitution of an apo-flavoenzyme (apo-GOD) on a 1.4 nm gold nano colloidal particle functionalized with the cofactor FAD has been done recently by Xiao et al. The electron transfer rate observed in this system was up to 5000 1 and thus significantly high than ever observed with the natural substrate oxygen (700 s-1). The noble metal particle acted as an electronic relay wiring the charge from the active site of the enzyme to the supporting electrode. 

FIG. 6. Background cyclic voltammograms in 50 mM NaNO, at 100 mV for (A) gold macro-disk electrode (B) 30NEE (C) lONEE. The geometric area for all electrodes was 0.079 cm. ... 

For example, Willner and co-workers accomplished electrical communication between glucose oxidase (GOx) and a gold electrode using molecular-level assembly.5,6 Unprecedentedly effective electron transfer was observed from the FAD moiety to the electrode through the Au-nano particles (electron transfer turnover rate, 4500 s-1), derived from molecular conjugation and bioconjugation. 

The nano-Au/PAMAM dendrimer/HRP assembly on a cystamine-modified gold electrode was found to show good sensitivity and stability in the detection of hydrogen peroxide [145],... 

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