Sandwich surface-enhanced Raman scattering (SERS) substrates (3S) utilizing coupling between continuous metal films and plasmonic particles were fabricated using silver mirrors, electrochemically roughened films, and various sizes of silver nanoparticles. The effect of excitation wavelength and nanoparticle size on SERS spectra of poly(vinylpyridine), selected as a model compound, was studied to determine the optimum conditions for the strongest SERS signal. The Raman enhancement resulted from the plasmon coupling of silver nanoparticles to the underlying continuous film as well as the lateral plasmon coupling between the silver nanoparticles. The formation of the charge transfer complex was also observed. The 3S configuration was used to obtain SERS spectra of dipicolinic acid (DPA), a chemical signature for Bacillus anthracis.

Mirror sandwich SERS substrates (M3S) were used to monitor the kinetics of Bacillus subtilis endospore germination. The sandwich configuration of the substrates allows real-time observation of germination in samples that contained only several hundred endospores. The enhancement provided by the substrates is attributed to the enhanced local electromagnetic field that originates from coupling between the Ag nanoparticles and the underlying metal film as well as from coupling between the Ag nanoparticles themselves. The germination kinetics at varying concentrations of l-alanine and different temperatures were studied by monitoring the intensity and growth of the Raman peak at 1010 cm(-1), which is characteristic of dipicolinic acid. A total of four concentrations (50, 75, 100, and 150 mM) of l-alanine and three different temperatures (30, 37, and 55 degrees C) were investigated.

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The C1 and C2 stereocenters of α-glucosaminides can be prepared by establishing the stereocenters in either order. For the former, a C2-azido glucosyl donor is prepared first, and the restraining effect of a 4,6-O-benzylidene ring is used to induce α-coupling. For the latter, the C1 linkage is prepared first by use of an npentenyl-manno-1,2-orthoester donor which ensures (a) clean α-coupling and (b) a convenient C2-ester. The C2-ester is replaced with a triflate leaving group, and nucleophilic displacement is effected by use of a hypervalent silicon azide.