Dendritic Gold Nanoparticles Towards Transparent and Electroactive Electrodes

Abstract: The combination of UV-visible absorption and electrochemical experiments (spectroelectrochemistry) enables to obtain highly specific spectroscopic information (in situ and operando) from modified surfaces. However, such application can be limited by the self-absorbance, for example, when metallic nanoparticles are present on modified surfaces. Indium-tin oxide onto glass (ITO) is a typical electrode commonly used for spectroelectrochemistry; ITO is an oxide-based semiconductor, and in numerous applications it is necessary to promote the modification of the electrode surface without significant loss of transparency. Here, we report a simple strategy to obtain ITO electrodes modified with self-assembled polyelectrolytes and active dendritic gold nanoparticles (AuNPs), a combination of soft and metallic materials that results in electrodes with significant optical transparency. Self-assembled poly(sodium styrene sulfonate) and polyamidoamine dendrimer (PSS/PAMAN bilayer) were applied successfully as efficient platform for monodisperse dendritic AuNPs electrodeposition, and the electrode containing those materials shows substantial optical transmittance from 400nm to 800nm. The combination of transparency and the presence of AuNPs homogeneously dispersed start to be a practical approach to develop metal-based electrodes for spectroelectrochemistry.

Key words indium tin oxide; gold nanoparticles; thin film; electrodeposition