Organized solid thin films of gold nanorods with different sizes for surface-enhanced raman scattering applications

10.1021/jp5086685Gold nanorods are among the most efficient structures for optical applications, especially in surface-enhanced Raman scattering applications. Notably, their use directly in colloidal solutions decreases their optical enhancing properties because of the impossibility of generating hot spots and the passivation of their surfaces by the surfactants used during their preparation, hindering the interaction of the analyte with the plasmonic surface. We present an easy and fast method for preparing organized lying-down nanorod films with particles of different aspect ratios, yielding efficient and clean plasmonic films populated with a large number of homogeneous hot spots

SERS chiral recognition and quantification of enantiomers through cyclodextrin supramolecular complexation

We introduce here a simple approach in which a cyclodextrin, functionalized with thiols in the narrower rim, is assembled onto the silver surface of a SERS platform composed of polystyrene beads coated with silver nanoparticles. Trapping properties of the fabricated sensor are demonstrated through the retention of different enantiomers (R,R or/and S,S) of hydrobenzoin (HBZ), a molecule that has not been reported before in SERS because it has no affinity for coinage metal surfaces. Further, selective recognition of each enantiomer and semiquantification of its proportion in a racemic mixture are provided by the analysis of the SERS spectra of the HBZ-cyclodextrin complex, in full agreement with the surface selection rules. Enantioselective sensor: We introduce a simple approach in which a cyclodextrin is assembled onto the silver surface of a SERS platform for chiral recognition of enantiomers (see picture). Trapping properties, chiral discrimination and quantification of the R,R- and S,S-enantiomers of hydrobenzoin by surface-enhanced Raman scattering (SERS) spectroscopy are demonstrated