A process is reported to obtain a nanoparticle sol from co-precipitated iron oxide particles without using any surfactant. The sol - a true ferrofluid - is not only stable over a wide range of pH but also in physiological solutions. This is a decisive step towards biomedical applications where nanoparticle agglomeration could so far only be prevented by using unwanted surfactants.

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 ...

Nanoparticle coated microspheres are composed of two or more materials with a core/shell structure and exhibit unique abilities that allow amplification of trace targets in immunoassays. The preparation of nanoparticle coated microspheres can be accomplished using three main strategies: (1) in-situ, (2) ex-situ, and (3) hollow sphere methods. Antibodies or biomolecules can be immobilized on the...

Nanotechnologies have been proposed for a variety of environmental applications, including subsurface characterization, enhanced oil recovery, and in situ contaminant remediation. For such applications, quantitative predictive models will be of great utility for system design and implementation. Electrolyte chemistry, which can vary substantially within subsurface pore waters, has been shown to...

Sensitive DNA detection is extremely important in clinical diagnostics, gene therapy, and a variety of biomedical studies. We have developed a novel DNA bioanalysis method with a 0.8 fM (0.8 x 10-15 M) detection limit using a bioconjugated fluorescent nanoparticle-based sandwich assay. An organic dye silica nanoparticle is synthesized using a modified reverse microemulsion. The nanoparticles ar...

The surface-enhanced Raman scattering (SERS) is mainly used as an analysis or detection tool of biological and chemical molecules. Since the last decade, alternative branch SERS effect has been explored, named shell-isolated nanoparticle spectroscopy (SHINERS) which was discovered in 2010. In SHINERS, plasmonic cores are for enhancing signal molecules, a very thin shell silica generally employe...