Sensing technologies based on metallic nanoparticles, known as Ag, Au, and so on, have raised enormous interest for their extraordinary sensing resolution and sensitivity to analytes of chemical or biological importance under optical detection have received wide attention in recent decades. Currently, a discrete nanoparticle in a free-standing form, either being organically or biologically modified on the nanoparticle surface, on a given substrate surface region has been employed for photosensing purpose. However, metallic nanoparticles suffering from physical and chemical instability such as oxidation, interparticle coupling, agglomeration, and so on during the processing stages may render undesirable outcomes, which further results in poorer performance than the theoretical expectation. Here we propose a facile and elegant concept to prepare an Ag-decorated silica nanoparticle (hereinafter termed core-shell SiO 2 @Ag nanosphere) based on the modified Sto ¨ber method. The Ag nanoparticles with an average size controlled at about 1, 3, and 5 nm deposited over the surface of the silica nanocarrier were well separated, making the resulting SiO 2 @Ag nanospheres. The nanospheres showed physically and optically stable surface plasmon resonance spectra and also demonstrated a relatively high Ag-sized dependent sensitivity to ppb level for the detection of analyte molecule, that is, melamine. Theoretical model fitting has been well managed to correlate the optical behavior of the nanosensors, and the outcomes strongly indicated a promising potential of the Ag-decorated SiO 2 core-shell nanospheres for sensory applications.

We describe a facile and one-step pulsed laser deposition (PLD) technique that was first time utilized to systematically fabricate a series of innovative Bi2Te3 superassembly-on-epitaxy bi-layer nanostructures uniquely coupling upper self-assembled well-ordered Bi2Te3 hierarchical nanostructures with unusually high surface-and interface-to-volume ratios and a highly electrical conductive epitaxial bottom thin layer on insulated SiO2/Si substrates as an emerging new class of the most advanced thermoelectric nanomaterials. The optimized power factor of the present superassembly-on-epitaxy films is one to three orders of magnitude higher than that of most Bi2Te3 nanoassemblies defined as assemblies of nanocrystals, evidently proving the significance and potential of the present new concept and resulting thermoelectric nanomaterials.

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A series of innovative heterogeneous nanocomposites comprising diamond-like carbon (DLC) clusters and well-aligned Bi–Sb–Te based nanoassemblies were realized for thermoelectric enhancement.