University of Houston System

Vanderbilt University

Wei-Chuan Shih

John Charles Wolfe

Yu-Lung Sung

Mufaddal Gheewala

Gopathy Purushothaman

Richard Coale Willson

Jingting Li

Fusheng Zhao

A lithography-free, mold-free method of fabricating high quality optical material by curing polydimethylsiloxane (PDMS) droplets in or on pre-heated substrates allows lenses with different focal lengths to be made by varying the volume and surface temperature, as well as the substrate.

Fabrication of polydimethylsiloxane optical material

The present disclosure relates to the fabrication and characterization of an optical fiber capable of firing light virtually from any point along its circumferential surface. The optical fiber is preferably prepared by laser micromachining. In preferred embodiments, laser radiation is focused onto a multimode optical fiber axis, forming a conical-shaped cavity (side window) in the fiber core. Because of the total internal reflection when the laser beam reaches the side window-outside medium interface, the beam is reflected to the side of the optical fiber.

Fabrication and applications of multiple side-window, side-firing optical fiber

A methodology for assays and diagnostics utilizes a nanoporous or corrugated metal-containing surface, fiber or particle which enhances or suppresses the optical detectability of a label. The resulting optical, electromagnetic, or imaging signal signals the presence of a pathogen or analyte of interest. Preferred embodiments pertain to label-free, in situ monitoring of individual DNA hybridization in microfluidics using molecular sentinel probes immobilized on nanoporous gold disks. By immobilizing molecular sentinel probes on nanoporous gold disks, single-molecule sensitivity is demonstrated via surface-enhanced Raman scattering which provides robust signals. The described methodology is generally applicable to most amplification independent assays and molecular diagnostics.

Nanoporous gold and silver nanoparticles and substrates for molecular and biomolecular sensing

A nanoporous metal can be formed by projecting laser patterns using a spatial light modulator (SLM) onto a gold/silver alloy film immersed in diluted nitric acid solutions. Heat accumulation induced by the photothermal effect enables localized dealloying in dilute nitric acid. NPG micropatterns can be formed at the irradiated spots while the surrounding alloy remains intact.

Patterning of nanoporous gold microstructures

An optrode may provide a cylindrical substrate with two or more electrodes deposited on said cylindrical substrate. The cylindrical substrate and electrodes may be coated by an insulating layer with openings or vias over certain portions of the electrodes that may provide a contact for the neural probe or may be utilized to connect lead lines. Manufacturing of an optrode may utilize a jig that secures a cylindrical substrate coated by a conductive material and a resist. A first mask may be positioned in an opening provided by the jig, and the cylindrical substrate may expose ions or neutral particles to define one or more electrode patterns. After regions of the resist and conductive material are removed to form the electrodes, a second mask may be utilized to define via regions in which portions of the electrodes are exposed and uncoated by an insulating layer.

Integrated thin-film optrode

A nanoporous gold disk (NPGD) as a novel surface-enhanced Raman spectroscopy (SERS) substrate. NPGD has SERS enhancement factor similar to that of gold nanoshells, but allows, for example, at least three times more benzenethiol molecules to be attached to its surface due to large surface-to-volume ratio. The high capacity enables the rapid detection of attomole-level benzenethiol molecules with relatively high detector temperatures. Additionally, a fabrication process to make NPGD with controlled size and highly reproducible SERS activities.

Nanoporous gold nanoparticles as high-payload molecular cargos, photothermal/photodynamic therapeutic agents, and ultrahigh surface-to- volume plasmonic sensors

A lithography-free, mold-free, single-step method of fabricating high quality optical lenses by curing polydimethylsiloxane (PDMS) droplets on a pre-heated smooth surface allows lenses with different focal lengths to be made by varying the droplet volume and surface temperature.

Fabrication of lenses by droplet formation on a pre-heated surface

An optrode may provide a cylindrical substrate two or more electrodes deposited said cylindrical substrate. The cylindrical substrate and electrodes may be coated by an insulating layer with openings or vias over certain portions of the electrodes that may provide a contact for the neural probe or may be utilized to connect lead lines. Manufacturing of an optrode may utilize a jig that secures a cylindrical substrate coated by a conductive material and a resist. A first mask may be positioned in an opening provided by the jig, and the cylindrical substrate may be exposed ions or neutral particles to define one or more electrode patterns. After regions of the resist and conductive material are removed to form the electrodes, a second mask may be utilized to define vias regions in which portions of the electrodes are exposed and uncoated by an insulating layer.

Method of fabricating a probe

Nanoporous gold nanoparticles as high-payload molecular cargos, photothermal/photodynamic therapeutic agents, and ultrahigh surface-to-volume plasmonic sensors

The present disclosure relates the use of a stamping surface enhanced Raman scattering (S-SERS) technique with nanoporous gold disk (NPGD) plasmonic substrates to produce a label-free, multiplexed molecular sensing and imaging technique. A NPGD SERS substrate is stamped onto a surface containing one or more target molecules, followed by SERS measurement of the target molecules located between the surface and SERS substrate. The target molecules may be deposited on the surface, which may be a carrier substrate such as polydimethylsiloxane (PDMS).

Method of stamping surface-enhance Raman spectroscopy for label-free, multiplexed, molecular sensing and imaging

An active-illumination parallel Raman microspectroscopy scheme for simultaneously collecting Raman spectra from multiple points in a full-spectra range. A combination of multi-point laser illumination with wide-field Raman imaging is employed in order to allow for simultaneous imaging of multiple points not aligned on a single line.

Method and system for active-illumination parallel Raman microspectroscopy

A neural probe includes a probe, wherein a tip of the probe is tapered; an insulating layer covering the probe, and one or more metallic traces, wherein the metallic traces are provide along the length of the probe. The probe also includes one or more contacts provided on the tip of the probe, wherein each of the one or more metallic traces terminates at the one or more contacts, and the one or more contacts provide an array of nanosized metallic pillars. The neural probe may also incorporate a lightguide. The lightguide may include an insulating layer providing a first cladding layer on the probe, a core layer provided on top of the first cladding layer, wherein the metallic traces and contacts are provided in the core layer with a core material, and a second cladding layer provided on top of the core layer.

Growing community of inventors

Houston, TX, United States of America

Wei-Chuan Shih