Design of Silica@Au Hybrid Nanostars for Enhanced SERS and Photothermal Effect.

Core-shell nanostructures of silicon oxide@noble metal have drawn a lot of interest due to their distinctive characteristics and minimal toxicity with remarkable biocompatibility. Due to the unique property of localized surface plasmon resonance (LSPR), plasmonic nanoparticles are being used as surface-enhanced Raman scattering (SERS) based detection of pollutants and photothermal (PT) agents in cancer therapy. Herein, we demonstrate the synthesis of multifunctional silica core - Au nanostars shell (SiO2 @Au NSs) nanostructures using surfactant free aqueous phase method. The SERS performance of the as-synthesized anisotropic core-shell NSs was examined using Rhodamine B (RhB) dye as a Raman probe and resulted in strong enhancement factor of 1.37×106 . Furthermore, SiO2 @Au NSs were also employed for PT killing of breast cancer cells and they exhibited a concentration-dependent increase in the photothermal effect. The SiO2 @Au NSs show remarkable photothermal conversion efficiency of up to 72 % which is unprecedented. As an outcome, our synthesized NIR active SiO2 @Au NSs are of pivotal importance to have their dual applications in SERS enhancement and PT effect.

Preclinical safety assessment of photoluminescent metal quantum clusters stabilized with autologous serum proteins for host specific theranostics.

Host derived serum proteome stabilised red-emitting gold quantum clusters (or Au-QC-NanoSera or QCNS) of size range ~2 nm have been synthesised in a first reported study. The host serum was taken from bovine, murine and human origins to establish the proof of concept. In-vitro biocompatibility with normal murine L929 fibroblast cells and radiosensitisation ability against PLC/PRF/5 hepatoma cells was established. A concentration dependant radiosensitisation effect of QCNS at differential γ-radiation doses was observed with almost 90% killing of cancer cells at a radiation dose of 5Gy. Acute and subacute safety, and non-immunogenicity of autologously derived QCNS was established in in-bred C57BL/6 mice. The biodistribution analysis revealed that the QCNS were effectively cleared from the body over a course of 28 days and were found to pose no major threat to the proper functioning and morphology of the mice.

Single source precursor route for the first graphene oxide-Pd6P nanocomposite: application in electrochemical hydrogen evolution reaction.

For the first time, Pd6P has been synthesised using a simple, straightforward and one-pot method i.e., thermolysis of a Pd(II) complex of a bidentate (P, N) organophosphorus ligand (anthracene-9-yl-CHN-CH2CH2-PPh2). The electrocatalyst (obtained after grafting nanospheres of Pd6P over layers of graphene oxide) shows high activity in electrochemical hydrogen evolution reactions (HER) with an overpotential of 133 mV to drive 10 mA cm-2 of cathodic current density. The GO-Pd6P nanocomposite is robust and effective for a continuous HER run for up to 16 hours.

Comparative toxicity evaluation of graphene oxide (GO) and zinc oxide (ZnO) nanoparticles on Drosophila melanogaster.

Engineered nanomaterials consisting of multiple nanoparticles (NPs) are finding their use in fields as wide and diverse as medicine, environment, cosmetics, energy and electronics. However, health and environmental impacts of these NPs need to be discerned individually to understand their true toxicity. Due to the promising application of upcoming material like GO-ZnO nanocomposite, the toxicity of ZnO and GO NPs was evaluated and compared individually in our study. This study compares the toxicity of Graphene Oxide (GO) NPs and Zinc Oxide (ZnO) NPs synthesized by Green method and Chemical method on Drosophila melanogaster. The GO, Chemical ZnO and Green ZnO NPs were synthesized and characterized using SEM, HR-TEM, FT-IR, UV-vis, EDX, XRD and DLS studies. NPs were comparatively analyzed for their cytotoxic and neurotoxic behaviors using different assays like MTT assay, mortality rate, larval crawling and climbing assay, total protein content analysis for evaluating the toxic potential of each of these NPs at different concentrations of use. Green ZnO were found to be least cytotoxic while Chemical ZnO caused the most cell damage. GO were found to have intermediary cytotoxicity. However, a different trend was observed with neurotoxicity wherein Green ZnO reportedly affected the neuromuscular coordination the most, while GO was found to have the least affect. This study provided insights into the different toxic effects caused by GO and ZnO NPs on Drosophila as well as comparative toxic effects of Chemical vs Green ZnO NPs.