Hexagonal patterns of gold nanorods were made by assembling gold nanorod-coated poly(N-isopropyl acrylamide) microgels. The required population of nanorods on the microgels was achieved by attaching nanoparticle seeds on the latter and growing them to nanorods. The various materials prepared were characterized by UV-vis spectroscopy and transmission electron microscopy. Similar experiments with...

We propose a family of exact solutions of Maxwell's equations to model some aspects of the imaging process involved in the scanning surface plasmon microscope (SSPM). More precisely, we compute the SSPM response of a spherical nanoparticle immobilized close to a thin gold layer and illuminated by a tightly focused spot. We discuss the influence of parameters such as the defocus and the width of...

A multicomponent nanostructure comprising of gold nanorod-nanoparticle (AuNR-AuNP) composites was fabricated to detect thrombin at subnanomolar concentrations in diluted human blood serum. Simulation and experiments revealed that the strong electromagnetic coupling resonance at the nanorod-nanoparticle junction of these probes can be used to construct highly sensitive SERS aptasensors.

Using in situ transmission electron microscopy, we demonstrated that gold nanoparticles are unified via "oriented attachment" assisted either by nanoparticle rotation or grain boundary migration at the attachment interface. We also observed that the combined nanoparticle changes shape with stable facet planes via surface diffusion, along with recrystallization.

We find that citrate-stabilized gold nanoparticles aggregate and precipitate in saline solutions below the NaCl concentration of many bodily fluids and blood plasma. Our experiments indicate that this is due to complexation of the citrate anions with Na+ cations in solution. A dramatically enhanced colloidal stability is achieved when bovine serum albumin is adsorbed to the gold nanoparticle su...

Oligonucleotide gold nanoparticle conjugates are being used as diagnostic tools and gene silencing experiments. Thiol-chemistry is mostly used to functionalize gold nanoparticles with oligonucleotides and to incorporate DNA or RNA molecules onto gold surfaces. However, the stability of such nucleic acid-gold nanoparticle conjugates in certain conditions may be a limitation due to premature brea...

Individual silver nanoparticle-conjugated target protein (cTnI) molecules on gold-nanopatterned chip were selectively detected by wavelength dependent-enhanced dark field illumination. Using specific nanoparticles with unique sizes and materials, the immunotargeted nanoparticle on the chips was detected at the single-molecule level by monitoring changes in the plasmonic resonance based on wavel...

We report multifunctional optical imaging using dye-coated gold nanorods. Three types of useful information, namely, Raman, fluorescence signals, and absorption contrast, can be obtained from a phantom experiment. These three kinds of information are detected in a nanoparticle-doped-phantom using diffuse optical imaging. Our novel nanoparticle could be used as a multimodality marker for future ...