Anomalous subsurface thermal behavior in tissue mimics upon near infrared irradiation mediated photothermal therapy.

Photothermal therapy using (Near Infrared) NIR region of EM spectrum is a fast emerging technology for cancer therapy. Different types of nanoparticles may be used for enhancing the treatment. Though the treatment protocols are developed based on experience driven estimated temperature increase in the tissue, it is not really known what spatiotemporal thermal behavior in the tissue is.

Functional hybrid nickel nanostructures as recyclable SERS substrates: detection of explosives and biowarfare agents.

We present the synthesis of highly anisotropic nickel nanowires (NWs) and large area, free-standing carpets extending over cm(2) area by simple solution phase chemistry. The materials can be post-synthetically manipulated to produce hybrid tubes, wires, and carpets by galvanic exchange reactions with Au(3+), Ag(+), Pt(2+), and Pd(2+). All of these structures, especially the hybrid carpets and tubes, have been prepared in bulk and are surface enhanced Raman scattering (SERS) active substrates.

Anisotropic nanomaterials: structure, growth, assembly, and functions.

Comprehensive knowledge over the shape of nanomaterials is a critical factor in designing devices with desired functions. Due to this reason, systematic efforts have been made to synthesize materials of diverse shape in the nanoscale regime. Anisotropic nanomaterials are a class of materials in which their properties are direction-dependent and more than one structural parameter is needed to describe them.

Bimetallic mesoflowers: region-specific overgrowth and substrate dependent surface-enhanced Raman scattering at single particle level.

A strategy for the preparation of bimetallic mesoflowers (MFs) has been demonstrated by a simple overgrowth reaction. We make hybrid MFs containing Au core and shells of different metals, such as Ag and Pt, by tuning the experimental conditions so as to study region-specific overgrowth. This selective growth is attributed to the specific binding affinity of cetyltrimethylammonium bromide (CTAB) at different crystal planes of Au MF surfaces.

Electric field assisted growth of highly surface enhanced Raman active gold nanotriangles.

A comparative study of the surface-enhanced Raman scattering (SERS) effect of the spherical gold nanoparticles (NPs) and highly uniform and oriented gold nanotriangles (NTs), anchored on indium tin oxide (ITO) coated conducting glass surfaces is reported. Contact and non-contact mode atomic force microscopic (AFM) analyses confirmed that all the triangles observed are equilateral and uniformly stacked. The NTs-coated ITO exhibited intense near-infrared (NIR) absorption and showed an extremely strong SERS activity than the spherical NPs.

Bimetallic flowers, beads, and buds: synthesis, characterization, and Raman imaging of unique mesostructures.

We demonstrate the creation of a new class of nano/mesostructures, such as Au/Ag flowers, Au/Pt buds, and Au/Pt beads, through the directed overgrowth of Ag or Pt on Au/oligoaniline nanowires (Au/OA NWs). Different stages of the formation of these mesostructures have been studied using various spectroscopic and microscopic techniques. The surface plasmon resonance (SPR) of the Au/OA NWs can be tuned by the incorporation of bimetallicity into the nanowire.

Wires, plates, flowers, needles, and core-shells: diverse nanostructures of gold using polyaniline templates.

A simple and versatile method for the synthesis of a wide range of polyaniline (PANI)-based 1D and 2D gold nanostructures of uniform size distribution with high colloidal stability is demonstrated. All the nanostructures were synthesized from oligoaniline-coated gold nanoparticle precursors. The nanostructures include nanowires of various sizes, nanoplates, and flower-like nanoparticles.