Short- and Long-Range Sensing on Gold Nanostructures, Deposited on Glass, Coated with Silicon Oxide Films of Different Thicknesses
Résumé
TThe paper reports on the possibility of short- and long-range plasmon sensing using transmission UV/vis spectroscopy. The influence of silicon oxide (SiOx) overlayers (0–310 nm), deposited on glass coated with gold nanostructures (formed by thermal evaporation and post-annealing at 500 °C) modified glass interfaces, on the localized surface plasmon resonance (LSPR) position and line shape was investigated. The rapid change in the LSPR spectrum for a thick overlayer suggests that it is possible to detect target molecules situated hundreds of nanometers away from the metal particle surface without loss of sensitivity. The hybridization of a covalently linked 15mer oligonucleotide strand on LSPR interfaces coated with 4, 35, and 151 nm thick SiOx was used to demonstrate the possibility of short- and long-range sensing. Comparable results were obtained in both cases.