Casein-graft-dextran copolymer was produced using the Maillard reaction. The copolymer is molecularly soluble in neutral aqueous solution whereas beta-carotene is extremely insoluble. By the method of dialysis or evaporation then dispersing in water, the solubility of hydrophobic complex of casein and beta-carotene decreases whereas the solubility of dextran increases gradually, then nanopartic...

Conversion of the greenhouse gas carbon dioxide (CO2) to value-added products is an important challenge for sustainable energy research, and nanomaterials offer a broad class of heterogeneous catalysts for such transformations. Here we report a molecular surface functionalization approach to tuning gold nanoparticle (Au NP) electrocatalysts for reduction of CO2 to CO. The N-heterocyclic (NHC) c...

The extensive use of gold nanoparticles (AuNPs) in nanomedicine, especially for intracellular imaging, photothermal therapy, and drug delivery, has necessitated the study of how functionalized AuNPs engage with living biological interfaces like the mammalian cell. Nanoparticle size, shape, surface charge, and surface functionality can affect the accumulation of functionalized AuNPs in cells. Co...

We discuss a plasmonic coupling device consisting of a periodic array of ellipsoidal silver nanoparticles embedded in SiO2 and placed near a silver surface. By tuning the shape of the particles in the array, the nanoparticle plasmon resonance is tuned. The resulting resonantly enhanced fields near the nanoparticles, in turn, excite surface plasmons on the metal film. We have performed finite in...

Using the Discrete Dipole Approximation we have studied the optical properties of different isolated nanoparticles with arbitrary shapes. We have investigated the main features in the optical spectra, depending of the geometry and size of such nanoparticles. We present and discuss our results in terms of the scattering, extinction and absorption optical coefficients, which can be directly compa...

Contamination of the environment with heavy metal ions has been an important concern throughout the world for decades. Here we discuss our recent effort on the development of a miniaturized and battery operated ultrasensitive gold nanoparticle based nanomaterial surface energy transfer (NSET) probe for screening toxic metal levels in contaminated soil, water and fish which has excellent sensiti...

The effects of shape on nanowire interactions and shear-induced ordering were studied. Both the normal and lateral forces were sensitive to the particles' curvature. (i) No adhesion was observed between the confining surfaces, and the force profiles were short-ranged and mostly reversible for straight wires but longer-ranged and irreversible for curved wires. (ii) Structural phase transitions c...

Nanoparticles are among the most important industrial catalysts, with applications ranging from chemical manufacturing to energy conversion and storage. Heterogeneity is a general feature among these nanoparticles, with their individual differences in size, shape, and surface sites leading to variable, particle-specific catalytic activity. Assessing the activity of individual nanoparticles, pre...

Nanoparticles are designed to deliver therapeutics and diagnostics selectively to tumors. Their size, shape, charge, material, coating, and cargo determine their individual functionalities. A systems approach could help predict the behavior of trillions of nanoparticles interacting in complex tumor environments. Engineering these nanosystems may lead to biomimetic strategies where interactions ...

We use stroboscopic quantitative phase microscopy to study cell deformation and the response to cavitation bubbles and transient shear stress resulting from laser-induced breakdown of an optically trapped nanoparticle. A bi-directional transient displacement of cytoplasm is observed during expansion and collapse of the cavitation bubble. In some cases, cell deformation is only observable at the...