USA As Represented by Secretary of the Navy

Mario Ancona

Igor L Medintz

John Bradley Boos

Arthur W Snow

Brian R Bennett

F Keith Perkins

W Russ Algar

James G Champlain

Hieu Bui

Melissa M Massey

Nicolas A Papanicolaou

Ellen R Goldman

Edward E Foos

Eddie L Chang

Sulay Jhaveri

Joseph S Melinger

Susan Buckhout-White

Francis J Kub

Karl D Hobart

Kimihiro Susumu

Eugene A Imhoff

Richard Magno

Theresa F Chick

Harvey S Newman

Sebastian A Diaz

James N Vranish

A nanoparticle (for example, quantum dot) serves as a substrate for immobilizing enzymes involved in consecutive reactions as a cascade. This results in a significant increase in the rate of catalysis as well as final product yield compared to non-immobilized enzymes.

Nanoparticle-attached enzyme cascades for accelerated multistep biocatalysis

Time-resolved nucleic acids include a long-lifetime FRET donor with an emission lifetime of at least one millisecond (such as a terbium complex), configured as a donor in a first FRET process, and at least one fluorescent dye with an emission lifetime of less than 100 nanoseconds configured as an acceptor in the FRET process. They can be configured as photonic wires, hybridization probes or beacons, and/or systems for computing logical operations.

Fluorescence-based computation system

Time-resolved nucleic acid hybridization probes

The stiffness and topology of ultra-small circular DNAs and DNA/peptide hybrids are exploited to create a transducer of enzyme activity with low error rates. The modularity and flexibility of the concept are illustrated by demonstrating various transducers that respond to either specific restriction endonucleases or to specific proteases. In all cases the output is a DNA oligo signal that, as we show, can readily be converted directly to an optical readout, or can serve as input for further processing, for example, using DNA logic or amplification. By exploiting the DNA hairpin (or stem-loop) structure and the phenomenon of strand displacement, an enzyme signal is converted into a DNA signal, in the manner of a transducer. This is valuable because a DNA signal can be readily amplified, combined, and processed as information.

Detection of enzyme activity with DNA loops

Protease transducers and sensors based on DNA loops

The stiffness and topology of ultra-small circular DNAs and DNA/peptide hybrids are exploited to create a transducer of enzyme activity with low error rates. The modularity and flexibility of the concept are illustrated by demonstrating various transducers that respond to either specific restriction endonucleases or to specific proteases. In all cases the output is a DNA oligo signal that, as we show, can readily be converted directly to an optical readout, or can serve as input for further processing, for example, using DNA logic or amplification By exploiting the DNA hairpin (or stem-loop) structure and the phenomenon of strand displacement, an enzyme signal is converted into a DNA signal, in the manner of a transducer. This is valuable because a DNA signal can be readily amplified, combined, and processed as information.

Enzyme transducers and sensors based on DNA loops

An apparatus and method for producing chemielectric point-sensor systems with increased sensitivity and increased selectivity. The chemielectric sensor system includes a sensor/heater assembly, where the sensor is a chemielectric sensor whose resistance or capacitance changes upon exposure to chemical analytes. The heater functionality applies a programmed sequence of one or more thermal pulses to the sensor to quickly raise its temperature. After each thermal pulse ends the change in resistivity of the sensor is measured. Such data as a function of the pulse time and temperature are recorded and analyzed to determine the chemical composition (selectivity) and concentrations in the ambient vapor by comparison to a library dataset. The sensor operation with fast thermal pulses also allows operation at higher frequencies where the noise is lower and hence sensitivity is improved.

Thermally pulsed chemielectric point sensing

Time-resolved nucleic acid hybridization beacons

The invention relates to a nanoscale antenna including a nucleic acid scaffold having a structure selected from the group consisting of a Holliday junction, a star, and a dendrimer; and a plurality of fluorophores attached to the scaffold and configured as a FRET cascade comprising at least three different types of fluorophores including at least one quantum dot, arranged with (a) a plurality of initial donor fluorophores fixed in exterior positions on the structure, (b) a terminal acceptor fluorophore fixed in a central position on the structure, and (c) a plurality of intermediate fluorophores fixed in positions on the scaffold between the initial acceptor fluorophores and the terminal acceptor fluorophores.

Quantum dots in modular nucleic acid scaffolds operable as nanoscale energy harvesting and focusing arrays

The invention relates to a nanoscale antenna including a nucleic acid scaffold having a structure selected from the group consisting of a Holliday junction, a star, and a dendrimer; and a plurality of fluorophores attached to the scaffold and configured as a FRET cascade comprising at least three different types of fluorophores, arranged with (a) a plurality of initial donor fluorophores fixed in exterior positions on the structure, (b) a terminal acceptor fluorophore fixed in a central position on the structure, and (c) a plurality of intermediate fluorophores fixed in positions on the scaffold between the initial acceptor fluorophores and the terminal acceptor fluorophores.

Use of modular nucleic acid scaffolds to create nanoscale energy harvesting and focusing arrays

A molecular concentrator comprising a thermal ratchet for driving molecules from one place to another. A plurality of linear, two-dimensional, and/or three-dimensional arrangements of heater structures are arranged on or suspended above a substrate. Each of the heater structures is configured to strongly sorb a vapor of interest when the heater structure is at room temperature and to rapidly desorb the vapor when the heater structure is at an elevated temperature. The vapor sorption of the individual heater structures is made selective by surface treatments, by monomolecular film depositions or by thicker absorbent polymer depositions. By selectively heating and cooling the heater structures, vapor molecules incident on the heater structures can be directed in a desired manner, e.g., from heater structures closest to a vapor-containing environment to a sensor.

Molecular concentrator based on thermal ratcheting

A semiconductor device including a heterostructure having at least one low-resistivity p-type GaSb quantum well is provided. The heterostructure includes a layer of InAlAs on an InP substrate, where the InAlAs is lattice matched to InP, followed by an AlAsSbbuffer layer on the InAlAs layer, an AlAsSbspacer layer on the AlAsSbbuffer layer, a GaSb quantum well layer on the AlAsSbspacer layer, an AlAsSbbarrier layer on the GaSb quantum well layer, an InAlSb etch-stop layer on the AlAsSbbarrier layer, and an InAs cap. The semiconductor device is suitable for use in low-power electronic devices such as field-effect transistors.

Low-resistivity p-type GaSb quantum wells

A molecular concentrator comprising a thermal ratchet for driving molecules from one place to another. A plurality of conducting wires are arranged on or suspended above a substrate. Each of the wires is configured to strongly sorb a vapor of interest when the wire is at room temperature and to rapidly desorb the vapor when the wire is at an elevated temperature. By selectively heating and cooling the wires, vapor molecules incident on the wires can be directed in a desired manner, e.g., from the wires closest to the vapor-containing environment to a sensor.

Silicon carbide PiN diodes are presented with reduced temperature coefficient crossover points by limited p type contact area to limit hole injection in the n type drift layer in order to provide a lower current at which the diode shifts from negative temperature coefficient to a positive temperature coefficient of forward voltage for mitigating thermal runaway.

Silicon carbide rectifier

A complementary metal oxide semiconductor (CMOS) device in which a single InGaSb quantum well serves as both an n-channel and a p-channel in the same device and a method for making the same. The InGaSb layer is part of a heterostructure that includes a Te-delta doped AlGaSb layer above the InGaSb layer on a portion of the structure. The portion of the structure without the Te-delta doped AlGaSb barrier layer can be fabricated into a p-FET by the use of appropriate source, gate, and drain terminals, and the portion of the structure retaining the Te-delta doped AlGaSb layer can be fabricated into an n-FET so that the structure forms a CMOS device, wherein the single InGaSb quantum well serves as the transport channel for both the n-FET portion and the p-FET portion of the heterostructure.

Growing community of inventors

Alexandria, VA, United States of America

Mario Ancona