properties of thermally dewetted thin au films on ito-coated glass for biosensing applications

Noble metal nanostructures are object of great interest due to their unique optical and electronic properties exploited in nanotechnology, medicine, biochemistry, and surface-enhanced spectroscopies. in this work, the au nanoparticle (np) structures for application in biosensing obtained by dewetting are investigated in dependence on their preparation conditions. structures are produced from thin au films (5–30 nm) sputtered onto the ito-coated glass substrates. the dewetting is performed by thermal treatment in ambient air. sem inspection of the structures reveal breakup of the au films into nps of rounded shape. the np size does not exceed 80 nm and their shape can be tuned by duration of the dewetting. in the absorbance spectra, the broad peaks centered around 550–620 nm are ascribed to resonant absorption of the surface plasmons and the estimated time of resonance damping is in the range of 2.24–3.65 fs. the large signal values observed in raman spectra, and the electrochemical performance confirm that the produced material can serve as an electrode for sensing applications.