University of California

Leland Stanford Junior University

Ondavia, Inc.

Seung Joon Lee

Carl D Meinhart

Brian Piorek

Martin Moskovits

Juan G Santiago

Sanjoy Banerjee

James M Bustillo

Richard M White

Casey Patrick Hare

Gregory A Campbell

Norman Douglas Bradley

Ioana Pavel

Provided are methods, devices and systems that utilize free-surface fluidics and SERS for analyte detection with high sensitivity and specificity. The molecules can be airborne agents, including but not limited to explosives, narcotics, hazardous chemicals, or other chemical species. The free-surface fluidic architecture is created using an open microchannel, and exhibits a large surface to volume ratio. The free-surface fluidic interface can filter interferent molecules, while concentrating airborne analyte molecules. The microchannel flow enables controlled aggregation of SERS-active probe particles in the flow, thereby enhancing the detector's sensitivity.

Device and methods of detection of airborne agents

Solid-type SERS-active substrates (e.g., noble metallic nanostructured powders or noble metallic nanoparticle-coatings on beads, microbeads, particles, etc.) are contained within optically-transparent modules. The modules allow for the controlled introduction of analyte-bearing fluid(s) into SERS-active substrates. The modules also allow for the monitoring of SERS signals emanating from analyte(s) which have accumulated on the confined SERS-active substrates. These SERS signals may be monitored over time by direct readout of the SERS substrates through the optically transparent module for chemical analysis and chemical detection applications.

SERS-active absorbers for the analysis of analytes

For a rapid and real-time SERS detection of organic chemicals in the air and the interfaces of air/solids, colloidal silver and/or gold nanoparticles solution is sprayed, in the form of nano-/micro-sized droplets, at the desired target area where the analytes of interest are present, e.g., in the air or onto certain organic/inorganic interfaces.

Nano-/micro-droplets for the detection of analytes

SERS-active materials are delivered to a remote zone, then optically interrogated to detect and analyze from a safe distance the presence of explosives or other materials which may or may not be hazardous. Delivery methods include deploying projectiles comprising SERS-active material(s) which distribute their contents upon deployment to a target zone.

SERS devices for the remote analysis of analytes

Methods and apparatus for detection and/or analysis of gas phase analytes and chemical compounds. The apparatus can be formed with microfluidic cells containing a selected fluid that interacts with the analyte(s), wherein the fluid can selectively transition between a vapor phase and a liquid phase. During condensation of the fluid, the population of analytes present within the vapor phase region of the fluid can be transported into the liquid phase region of the fluid within the microfluidic cells. During evaporation of the fluid, the analytes can be substantially retained within liquid phase region of the fluid and within the cells. Repetitive cycling of this vapor/liquid exchange can provide a build-up of the analytes within the microfluidic cells where they can be detected/analyzed.

Methods and apparatus for transport of airborne molecules using an active cyclical vapor/liquid exchange

Methods of analysis, and compositions relating to such, to determine the presence or absence of an analyte in a sample utilizing a composite substrate which facilitates surface enhanced Raman spectroscopy through the use of 'hot spots' of the form 'metal/analyte/metal' are presented. Additionally, substrates which contain &#x2018;hot spots&#x2019; of the form &#x2018;metal/analyte/metal&#x2019; and substrates which facilitate the formation of &#x2018;hot spots&#x2019; of the form &#x2018;metal/analyte/metal&#x2019; are presented as well as methods for making these substrates.

Platform for chemical and biological sensing by surface-enhanced Raman spectroscopy

A self-excited microelectromechanical device is described. The device includes a resonating structure, such as a cantilever, which responds to a physical phenomenon by generating an induced variable frequency voltage signal corresponding to the physical phenomenon. Self-excitation circuitry connected to the cantilever processes the induced variable frequency voltage signal and produces a variable frequency voltage signal in a resonant pass band of interest that is applied to the cantilever to augment the effect of the physical phenomenon on the cantilever. An exemplary use of the device is as a power line sensor. In this context, the cantilever responds to the electric field associated with a power signal on a power line. The cantilever transforms the voltage signal of the electric field into a corresponding frequency signal. The noise-immune frequency signal can be readily processed to reconstruct the power signals carried by the power line.

Growing community of inventors

Santa Barbara, CA, United States of America

Seung Joon Lee