Surface acoustic wave response to optical absorption by graphene composite film.

Propagation of surface acoustic waves in YZ LiNbO3 overlaid with graphene flakes has been investigated and its optical response to illumination by 633-nm light from a He-Ne laser was studied. The heating of the sample surface caused by optical absorption by the graphene led to a downshift in the transmitted SAW phase caused by the wave velocity's dependence on temperature. The proposed simple model based on optothermal SAW phase modulation was found to be in good agreement with the experimental results.

Electroluminescence of nanopatterned silicon with carbon implantation and solid phase epitaxial regrowth.

Electroluminescence at 1.28mum is observed in a nanopatterned silicon test structure that has been subjected to carbon implantation followed by solid-phase epitaxial regrowth for recrystalization. The sub-bandgap luminescence comes from a di-carbon complex known as 'G center'. Enrichment of silicon with carbon atoms has been achieved in a procedure consisting of two implantations and solid-phase epitaxial regrowth. Nanopatterning was done using an anodized aluminum oxide membrane as a mask for reactive ion etching. Along with the electroluminescence, an enhanced photoluminescence was measured.

DNA-directed synthesis of zinc oxide nanowires on carbon nanotube tips.

This paper describes a class of three component hybrid nanowires templated by DNA directed self-assembly. Through the modification of carbon nanotube (CNT) termini with synthetic DNA oligonucleotides, gold nanoparticles are delivered, via DNA hybridization, to CNT tips that then serve as growth sites for zinc oxide (ZnO) nanowires. The structures we have generated using DNA templating represent an advance toward building higher order sequenced one dimensional nanostructures with rational control.

Electric field tuning of plasmonic response of nanodot array in liquid crystal matrix.

In this work we demonstrate the feasibility of electric-field tuning of the plasmonic spectrum of a novel gold nanodot array in a liquid crystal matrix. As opposed to previously reported microscopically observed near-field spectral tuning of individual gold nanoparticles, this system exhibits macroscopic far-field spectral tuning. The nanodot-liquid crystal matrix also displays strong anisotropic absorption characteristics, which can be effectively described as a collective ensemble within a composite matrix in the lateral dimension and a group of noninteracting individual particles in the normal direction. The effective medium model and the Mie theory are employed to describe the experimental results.

Ultrasensitive electrocatalytic DNA detection at two- and three-dimensional nanoelectrodes.

Electrochemical DNA detection systems are an attractive approach to the development of multiplexed, high-throughput DNA analysis systems for clinical and research applications. We have engineered a new class of nanoelectrode ensembles (NEEs) that constitute a useful platform for biomolecular electrochemical sensing. High-sensitivity DNA detection was achieved at oligonucleotide-functionalized NEEs using a label-free electrocatalytic assay. Attomole levels of DNA were detected using the NEEs, validating the promise of nanoarchitectures for ultrasensitive biosensing.