Abhijit Manna

Gold Nanoparticles Used as a Carrier Enhance Production of Anti-Hapten IgG in Rabbit: A Study with Azobenzene-Dye as a Hapten Presented on the Entire Surface of Gold Nanoparticles

The azobenzene moiety, well-known not only for its reversible cis-to-trans photoisomerization but also as a hapten, does not induce antibodies on its own, but it reacts with antibodies raised against conjugates with protein carriers. Hence we selected azobenzene dye as an indicator to assess the possibility of having gold nano-particles act as an immunological carrier instead of protein carriers. In rabbits, we confirmed an in vivo response against azobenzene dye presented on the entire surface of gold nanoparticles (azo-nanoparticles), where the gold nanoparticles appeared to play a role as a carrier for the hapten. A high yield of immunoglobulin G (IgG) against the azobenzene derivative took place in rabbits injected with azo-nanoparticles, whereas no increase in IgG was recognized in other rabbits treated solely with chemically equivalent azobenzene dye instead of azo-nanoparticles. Electron microscopy and surface plasmon resonance spectroscopy indicated that the IgG obtained specifically recognized the difference between the isomer conformations of the azobenzene moiety.

Gold Nanoparticles Surface-confined by Hybrid Self-Assembled Monolayers of Dendrimer and Dodecanethiol

Gold nanoparticles surface-confined by hybrid self-assembled monolayers (SAMs) were synthesized by replacement of dendrimer-passivated nanoparticles by dodecanethiol. Transmission electron microscopy, small-angle X-ray scattering (SAXS), infrared absorption spectroscopy, 1H NMR and elemental analysis were performed to characterize hybrid-layer-passivated nanoparticles. The hybrid particles were separated into domains of small and large spheres. This indicates that the replacement may be dependent on the particle size.

NANOSCOPIC BUILDING BLOCKS FROM POLYMERS, METALS, AND SEMICONDUCTORS FOR HYBRID ARCHITECTURES

This paper describes some of our eorts in the area of nanostructured thin lm architectures. The resulting interfacial hybrid assemblies are built from (1) organic/polymeric objects based on dendrimer systems, from (2) surface-functionalized Au nanoparticles, and (3) from a variety of semiconducting quantum dots. Dendrimers as polymeric building blocks with a strictly monodisperse particle size distribution in the nanometer range can be functionalized in the core, the scaold, or at the periphery, thus oering interesting hybrid materials for a wide range of applications. The combination with Au clusters and their local surface plasmon resonances suggests new strategies for optoelectronic devices or unconventional bio-sensor platforms. The possibility of tuning the luminescent properties of semiconducting nanoparticles by size or compositional bandgap engineering complements the assembly kit with building blocks for supramolecular thin lm nanocomposite materials.