Nanoscopic Properties and Application of Mix-and-Match Plasmonic Surfaces for Microscopic SERS

Abstract

Gold and silver nanoparticles can be immobilized on glass slides using aminosilane linkers. Here, we demonstrate that particle monolayer surfaces can also be generated by simultaneous immobilization of both gold and silver nanoparticles with the same organosilane linker. These new surfaces display surface-enhanced Raman scattering (SERS) enhancement typical for gold or silver monolayers, depending on the ratio of the two types of nanoparticles and, at the same time, have the capability to probe complex analytes composed from various molecules which adsorb at only one of the metals. The reported results from scanning electron microscopy, scanning force microscopy, and UV/vis absorbance for surfaces containing one or two types of nanoparticles indicate that an enhancement level above 104 is related to nanoaggregates that form in the 2D plane. High and stable enhancement factors over a wide range of analyte concentrations along with high homogeneity of the enhancement at the microscopic scale make the plasmonic nanoparticle mix-and-match surfaces ideal substrates for use in microscopic SERS sensing.

Identification of aqueous pollen extracts using surface enhanced Raman scattering (SERS) and pattern recognition methods

“…As opposed to attaining high reproducibility SERS spectra by using immobilized nanoparticles , we show now that species‐specific classification of pollen extract SERS data is possible with high numbers of spectra that are obtained very quickly with simple nanoparticle solutions. To make use of this high amount of hyperspectral data, automated pattern recognition tools, in particular artificial neural networks (ANN), are applied.…”

Taxonomic relationships of pollens from matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry data using multivariate statistics

“…Optical and spectroscopic methods, also in combination with morphological information, have been shown to be applicable for pollen characterization and classification. Sensitive Raman spectroscopic tools, specifically Raman mapping and resonant Raman scattering, were used to characterize small physiological changes and selected biomolecular species in pollen grains …”

Immune recognition construct plasmonic dimer for SERS‐based bioassay

“…The detection strategy for the biotin method is shown schematically in Scheme . The immobilization of the NPs renders them stable in the presence of changes in analyte type and concentration . Thus, in this study, the silicon slide was first covered with BSA–biotin and passivated with BSA and then coated with streptavidin‐decorated gold NPs that can specifically recognize biotin (Fig.…”