address correspondence to: Prof. Carlos Rinaldi, Po Box 9046, Mayagüez, PR 00681. tel: 787-832-4040 ext 3585 • Fax: 787-265-3818 • email: crinaldi@ uprm.edu Nanoparticle systems are an intense subject of research for various biomedical applications. Colloidal suspensions of magnetic nanoparticles are of special interest, particularly in bioimaging, and more recently, in Magnetic Fluid Hyperther...

Silver nanoparticles deposited on quartz substrates are widely used as SERS substrates. The nanoparticles can be deposited directly from colloidal solution by dipping technique. However, the adhesion of the particles on the quartz surface is very poor. Normally the substrate is pre-treated with hydroxylation or silanisation process. In this paper, we have demonstrated that the application of th...

In recent years, there has been dramatic progress in the photonics field in disordered media, ranging from applications in solar collectors, photocatalyzers, random lasing, and other novel photonic functions, to investigations into fundamental topics, such as light confinement and other phenomena involving photon interactions. This paper reports several pieces of experimental evidence of locali...

We present a reproducible, one-pot colloidal co-assembly approach that results in large-scale, highly ordered porous silica films with embedded, uniformly distributed, accessible gold nanoparticles. The unique coloration of these inverse opal films combines iridescence with plasmonic effects. The coupled optical properties are easily tunable either by changing the concentration of added nanopar...

Aggregation of colloidal nanoparticles in the presence of shear is a key step in processing of many particulate materials, polymeric nanoparticles, food products etc. Predicting the rate of aggregation is importance in order to optimize the operating conditions under which coagulation takes place. In this work, we have performed detailed simulations of the aggregation rate of colloidal nanopart...

Nanoparticle-ligand systems can be targeted to specific analytes to effect a change in the properties of the nanoparticles. We will examine two examples in which the electromagnetic properties of the nanoparticles (arising from their small size) are altered by analyte binding, and can be applied as a transducer in a chemical sensing system for explosive analytes. The first property reviewed is ...

Plasmonic metal nanostructures have shown great potential in sensing applications. Among various materials and structures, monolithic nanoporous gold disks (NPGD) have several unique features such as three-dimensional (3D) porous network, large surface area, tunable plasmonic resonance, high-density hot-spots, and excellent architectural integrity and environmental stability. They exhibit a gre...

Highly effective separation of colloidal gold nanorods/nanoplates from co-produced isotropic nanoparticles has been achieved by selective precipitation triggered by salt.

Recognizing the significance of the life stage of fish for nano-eco-toxicological studies, the acute toxicity of colloidal silver nanoparticles (AgNPs) was tested in three different life stages of rainbow trout. Fishes were exposed to colloidal AgNPs at nominal concentrations of 100, 32, 10, 3.2, 1, 0.32, 0.1, and 0.032 mg/L. The estimated 96 hr LC50 values were 0.25, 0.71, and 2.16 mg/L for th...

Nanofluids, i.e., colloidal dispersions of nanoparticles in a base liquid (solvent), have received considerable attention in the last years due to their potential applications. One attractive feature of these systems is that their thermal conductivity can exceed the corresponding values of the base fluid and of the fluid with large particles of the same chemical composition. However, there is a...