Colorimetric and Label-Free Optical Detection of Pb Ions via Colloidal Gold Nanoparticles.

The detection of the lead heavy metal (Pb) in water is crucial in many chemical processes, as it is associated with serious health hazards. Here, we report the selective and precise colorimetric detection of Pb ions in water, exploiting the aggregation and self-assembly mechanisms of glutathione (GSH)-functionalized gold nanoparticles (GNPs). The carboxyl functional groups are able to create coordination complexes with Pb, inducing aggregation amongst the GSH-GNPs in the presence of Pb due to the chelation of the GSH ligands.

Publisher Correction: Surface Modification and Charge Injection in a Nanocomposite Of Metal Nanoparticles and Semiconductor Oxide Nanostructures.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Surface Modification and Charge Injection in a Nanocomposite Of Metal Nanoparticles and Semiconductor Oxide Nanostructures.

Combining two materials in a nanoscale level can create a composite with new functionalities and improvements in their physical and chemical properties. Here we present a high-throughput approach to produce a nanocomposite consisting of metal nanoparticles and semiconductor oxide nanostructures. Volmer-Weber growth, though unfavorable for thin films, promotes nucleation of dense and isolated metal nanoparticles on crystalline oxide nanostructures, resulting in new material properties.

Topographically Engineered Large Scale Nanostructures for Plasmonic Biosensing.

We demonstrate that a nanostructured metal thin film can achieve enhanced transmission efficiency and sharp resonances and use a large-scale and high-throughput nanofabrication technique for the plasmonic structures. The fabrication technique combines the features of nanoimprint and soft lithography to topographically construct metal thin films with nanoscale patterns. Metal nanogratings developed using this method show significantly enhanced optical transmission (up to a one-order-of-magnitude enhancement) and sharp resonances with full width at half maximum (FWHM) of ~15 nm in the zero-order transmission using an incoherent white light source.

Quantum-dot-conjugated graphene oxide as an optical tool for biosensor.

We have demonstrated a novel platform of quantum dots (QDs) core-shell conjugated graphene oxide (GO) biosensor for effective protein detection. The advantage in making core shell nanostructure allows preserving stable QDs, by improving quantum yield, and lowering the toxicity of the core. Both QDs and GO are efficient nanoparticle systems that can potentially be used for drug delivery, diagnosis, and biosensors scaffolds.

Enhanced optical transmission and Fano resonance through a nanostructured metal thin film.

Artificial and engineered nanostructures expand the degrees of freedom with which one can manipulate the intricate interplay of light and matter. Certain nanostructural arrangements in the excited state enable the efficient electromagnetic coupling of propagating light with localized fields. Here, we demonstrate that light transmitted through a nanostructured metal thin film without any apertures can be significantly enhanced.