Electrode multilayered nanoparticle

The main idea demonstrated by Willner and coworkers [20] is the ability to construct multilayered nanoparticle electrodes, which are porous. In a related study Patolsky et al. extended this idea further using biocatalysts to detect H2O2 [18]. In this example, the construction of the electrode is similar to the one described above but the redox-active bridging molecule was replaced with microperoxidase-11 (MP-11). 

Fig. 7.3b Schematic diagram of multilayer thin films of CdS nanoparticles on Au electrode in presence of poly allylamine hydrogen chloride.

The dynamics of self-exchange between the MFCs is probed by linking them through carboxylate-metal ion-carboxylate bridges [121] on an electrode surface. The diffusion-like electron transport in multilayer films is used to obtain information on the nanoparticle-nanoparticle electron transfer dynamics. Potential step experiments that give an idea of the rate of electron hopping (electron diffusion)... 

Bulk nanostructured materials are soUds with nanosized microstructure. Their basic units are usually nanoparticles. Several properties of nanoparticles are useful for applications in electrochemical sensors [67], However, their catalytic behavior is one of the most important. The high ratio of surface atoms with free valences to the total atoms has led to the catalytic activity of nanostructured SEs being used in electrochemical reactions. The catalytic properties of nanoparticles could decrease the overpotential of electrochemical reactions and even provide reversibility of redox reactions, which are irreversible at the bulk metal SE [68], Multilayers of conductive nanoparticles assembled on electrode surfaces produce a high porous surface with a controlled microenviromnent. These structures could be thought of as assemblies of nanoelectrodes with controllable areas. 

Sun, Y., Yan, F., Yang, W., Sun, C., 2006. Multilayered construction of glucose oxidase and silica nanoparticles on Au electrodes based on layer-bylayer covalent attachment. Biomaterials 27, 4042. 

Multilayers of PS colloidal crystals assembled on the electrode surface were also used as the template for electropolymerization of aniline. Nanoporous or nanocomposite films of PANl may be produced with or without the removal of the PS template. Better stability and reproducibility of the nanocomposite film have been observed than the nanoporous PANl film. The reason for this was the PS nanoparticles enable the PANl/PS composite film to maintain its morphology, since the nanoporous PANl film may suffer from collapse or shrinkage. Insulating pol3mier nanoparticles can also be electrochemically codeposited into the CP matrix by grafting their surfaces with reactive moieties,i.e., a PPy-PEG-PLA nanocomposite film can be prepared. [PEG-PLA poly(l-ethoxyethylglycidyl ether)-block-poly(L-lactide) copol5mier]. 

---