A simple N,N'-dicyclohexylurea adduct of ß-alanine can self-assemble to generate nano-morphological versatility in response to different environmental conditions.

A single ω-amino acid based molecule "Boc-ß-Ala-N,N'-dicyclohexylurea" can form diverse nanostructures such as nano-vesicles, nano-tubes, nano-rods and nano-fibrils by self-assembly, in response to various environmental conditions. Interestingly, the nano-vesicular structures generated from this molecule can encapsulate the highly potent anticancer drug methotrexate, which can be released by salt triggered disruption of these vesicles. This phenomenon indicates the probability of its use in targeted delivery of drugs or any bio-active molecule, utilizing this encapsulation efficiency. Moreover, a surface-induced morphological transformation of these nano-vesicles to nano-fibers can be realized while they interact with hydrocarbon-functionalized surfaces. This phenomenon indicates the probability of their utilization in model study of peptide interaction behavior at liquid-solid interfaces and can be used in advanced study of various biological phenomena and bio-technological applications.

Study of the nano-morphological versatility by self-assembly of a peptide mimetic molecule in response to physical and chemical stimuli.

A small peptide mimetic molecule can form diverse nanostructures such as nano-vesicles, nano-tubes and nano-ribbons/fibrils by self-assembly, in response to various physical and chemical stimulations.

Effect of surface plasmon resonance on the photocatalytic activity of Au/TiO2 under UV/visible illumination.

In this study, gold-loaded titanium dioxide was prepared by an impregnation method to investigate the effect of surface plasmon resonance (SPR) on photoactivity. The deposited gold nanoparticles (NPs) absorb visible light because of SPR. The effects of both the gold content and the TiO2 size of Au/TiO2 on SPR and the photocatalytic efficiency were investigated. The morphology, crystal structure, light absorption, emission from the recombination of a photoexcited electron and hole, and the degree of aggregation were investigated using transmission electron microscopy (TEM), X-ray diffraction (XRD), UV-visible-diffuse reflectance spectra (UV-VIS-DRS), photoluminescence (PL) spectroscopy, and turbidimetry, respectively. Photocatalytic activity was evaluated by the decolorization of methyl orange solution over modified titania under UV and UV/GLED (green light emitting diode) illumination. Au/TiO2 NPs exhibited an absorption peak (530-570 nm) because of SPR. The results of our photocatalytic experiments indicated that the UV-inducedly photocatalytic reaction rate was improved by simultaneously using UV and green light illumination; this corresponds to the adsorption region of SPR. Au/TiO2 could use the enhanced electric field amplitude on the surface of the Au particle in the spectral vicinity of its plasmon resonance and thus improve the photoactivity. Experimental results show that the synergistic effect between UV and green light for the improvement of photoactivity increases with increasing the SPR absorption, which in turn is affected by the Au content and TiO2 size.