YBa₂Cu₃O_7−δ matrix-induced in situ growth of plasmonic Au nanoparticles for biological sensor devices

The authors present a novel method of fabricating crystalline gold nanoparticles used in plasmonic application. The preparation and characterization of monocrystalline Au nanoparticles with diameters between 10 and 100 nm embedded in an YBa₂Cu₃O_7−δ matrix is presented as well as a future vision of structured particle arrangements by photolithographic procedures. To use these particles for biological applications, the matrix may has to be dissolved to obtain extracted nanoparticles on a dielectric substrate. Whether the nanoparticles change their position during the extraction process is investigated and the realized dissolving procedure by citric acid solution is shown. The dissolution of the matrix thereby is investigated by X-ray diffraction experiments and energy-dispersive X-ray spectroscopy. Furthermore, the spectral characterization by particle selection is illustrated based on microspectroscopy.