Electrocatalysis distance between electrodes

The effect of the distance between the active center and the electrode on the reaction rate has been studied using as an example the electrocatalysis of the oxygen reduction reaction by laccase adsorbed on soot. Variation in the distance between the active center and the electroconductive substrate was achieved by inserting an intermediate monolayer of lipid molecules flatly and vertically oriented cholesterol molecules and vertically oriented lecithin molecules (scheme in Figure 36). In this case, the conditions of obtaining compact lipid monolayers were fulfilled. The subsequent setting of laccase did not lead to their desorption. 

AuNPs inserted between the electrode surface and redox metalloproteins therefore both work as effective molecular linkers and exert eflfident electrocatalysis. Recent considerations based on resonance turmeling between the electrode and the molecule via the AuNP as a mechanism for enhanced interfadal ET rates suggest that electronic spillover rather than energetic resonance is a hkely origin of the effects (J. Kleis et al., work in progress). Even slightly enhanced spillover compared with a planar Au(lll) surface is enough to enhance the ET rate by the observed amount over a 10-15 A ET distance. 

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