Properties of an Indium Tin Oxide Electrode Modified by a Laser Nanostructured Thin Au Film for Biosensing

Structural, optical, and electrochemical characteristics of the indium tin oxide (ITO) electrode modified by Au nanoparticle (NPs) produced by pulsed UV laser irradiation of thin films are investigated in this work. Properties of the NP arrays depend on the film thickness and parameters of the laser interaction. Semi-regular structures characterized by broad size distributions of mean values ca. 62-92 nm are observed in the SEM images. In absorbance spectra the plasmon resonance peaks located around 544 nm reveal an IR shift and an increase of damping of the plasmonic enhancement with increasing NP size. Despite the broad size distribution and negative effect of damping that results in plasmon decay times of below 3.2 fs, the ITO electrode modified by Au NP arrays shows marked improvement of the electrochemical activity towards the Fe2+/Fe3+ redox couple and also glucose. Results obtained for non-enzymatic glucose detection indicate the potential for cost-effective solutions in the area of biosensing.