American Research Corporation of Virginia

Luna Innovations Inc.

Shufang Luo

Howard P Groger

Russell J Churchill

K Peter Lo

Martin Weiss

Kent A Murphy

Michael B Miller

Jennifer L Elster

Steven A Stevenson

Harry C Dorn

Peter Lo

Yongcheng Liu

Janice P Stevenson

Artur Sucheta

James M Sloan

Various exemplary embodiments, devices, systems, and methods for sensing moisture are disclosed, including at least one moisture sensor that comprises an optical fiber, a long period grating formed in at least a portion of the optical fiber, and a layer of PEI bonded to the long period grating. One exemplary embodiment comprises a system for measuring humidity, the system comprising an optical fiber moisture sensor having a mono-layer of PEI covalently-bonded to an outer surface of said optical fiber, a processor coupled to said optical fiber moisture sensor, and a moisture indicator coupled to said processor.

Devices, systems, and methods for sensing moisture

A highly-sensitive, rapid response fluorescent probe is based on the affinity of a polymer matrix for an analyte of interest. The probe includes a polymer matrix and a dye immobilized in the matrix. The polymer matrix has an affinity for an analyte of interest and the dye has little or no sensitivity to the analyte of interest when excited by an excitation source in a free state but has significant sensitivity to the analyte of interest when excited by the excitation source when immobilized in the matrix. Sensors incorporating the polymer/fluorophore probes of the present invention have the sensitivity and rapid response needed for detection of chemical agent and biological materials. Sensors using the probes provide sensitivity to Sarin at several hundred parts per trillion in one second or less. That is a notable advance over state-of-the-art detectors that require preconcentration steps, which in turn restrict response times to one minute or more. A wide-range of near-infrared excitable fluorophores are used as sensitive probes for analytes not detectable when the fluorophores are outside the polymer matrix. The present sensors provide early warning of the presence of toxic chemicals, provides for on-line analysis of trace materials in chemical and biological processing operations and biomedical processing operations, and provides for effective biomedical and environmental monitoring.

Fluorescent probes based on the affinity of a polymer matrix for an analyte of interest

A method for imagining and treating a body employing at least one trimetallic nitride template endohedral metallofullerene compound is disclosed. The compound has at least one diagnostic and at least one treatment atom encapsulated within a fullerene cage. The two atoms are different from each other. The compound is administered into a body, traced, and allowed to react at a targeted area of the body.

Imaging and treatment method for body

An optical fiber fluorescence sensor system capable of compensating fiber bending loss is provided. The system uses a modulated light-emitting diode and digital-signal processing chips to enhance the measurement of fluorescence signals. A fiber-optic oxygen sensor system suitable for measuring oxygen levels in gas and in aqueous media is provided. The system alleviates fiber bending loss. Detection of the signal-to-noise ratio of the system which exceeds 30 dB is done by using inexpensive components.

Loss compensation using digital-signal processing in fiber-optic fluorescence sensors

Optical chemical probes have layers of anionic and cationic polyelectrolytes and one or more dyes incorporated into these layers. The probes are placed into the medium and the dye or dyes react in the presence of the corresponding chemical. Color changes may be observed manually or by a photo detector. A light source may be employed to increase the optical signal received from the probe. Further, a waveguide may be used to trap multiple optical signals. The invention is used for chemical analysis.

Optical chemical sensor based on multilayer self-assembled thin film

An apparatus and its accompanying method measures fluorescence decay, fluorescence amplitude and fluorescence polarization. The instrument includes a light emitting diode or laser diode light source, an amplified photodiode detector, and electronics and software for calculating the phase of the fluorescence from the computed inner product of the scattering and fluorescence signals. The electronics for measuring fluorescence decay includes two signal synthesizers, two downconverters, a simultaneously sampling analog-to-digital converter and means for calculating the inner product of the downconverted waveforms. A signal source, preferably a direct digital synthesizer, is used in combination with a digital-to-analog converter to provide a controllable output signal. That signal drives a modulatable light source, which is a light emitting diode, a laser diode or a combination of the two. Excitation light from the light source excites the sample fluorophore which is immobilized in a solid material. Fluorescence is detected using an amplified photodiode. The received signal is downconverted using a pair of mixers. The downconverted signals are digitized and stored. Preferably, the signals are digitized using a two-channel synchronous analog-to-digital converter controlled by a digital signal processor. Data from each channel are multiplied and summed to provide the inner product.

Fluorescence decay measurement by calculation of inner product

A fluorescent sensor for chemical analysis has a light source, an optical waveguide, and a detector. Fluorophores are associated with the optical waveguide. When an impervious waveguide is used, a fluorophore-containing layer is applied to a surface of the waveguide. The fluorophores are excited by a laser, a light emitting diode, an electroluminescent source or a lamp source emitting light propagating at angles to the waveguide. The light source is modulated. A mirror can be used to direct the light beam. The angle of light incidence on the waveguide can be altered by moving the waveguide itself. The waveguide traps the laser-induced fluorescence and projects fluorescence signals through a suitable filter to a photodetector or otherwise wavelength-specific photodetector positioned near the waveguide structure. Remote operation of the sensor is achieved using optical fibers. Patterned waveguides allow multiple excitation sources to illuminate multiple fluorescent probe materials. The change in fluorescence from each fluorophore is sensed as a vector response which is evaluated using digital signal processing. The sensor uses steady state fluorescence and fluorescence decay information to determine identity and concentration of analytes of interest. The invention is used for chemical analysis of gases or of liquid materials.

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Blacksburg, VA, United States of America

Shufang Luo