Abstract: The present invention includes a method and system for enhancing the signal-to-noise ratio in emission detection comprising: selecting a probe capable of at least one of fluorescence, phosphorescence, or delayed fluorescence in or about a sample that comprises interfering background signal; and exposing the probe to one or more controllable bursts, each burst comprising two or more pulses, wherein the one or more controllable bursts of high repetition energy pulses enhance the signal from the probe above that of the background signal.

Abstract: The present invention includes compositions and methods for fluorescence-based multiplex probe to simultaneously detect one or more enzymatic activities comprising: a first enzymatic target having a first end and a second end, wherein the first end of the first enzymatic target is attached to a central body and the second end of the first enzymatic target is attached to a first fluorophore; a second enzymatic target having a first end and a second end, wherein the first end of the second enzymatic target is attached to the central body and the second end of the second enzymatic target is attached to a third fluorophore; wherein the central body comprises at least one second fluorophore; wherein the first enzymatic target comprises a specific cleavage site of a first enzyme that cleaves the first enzymatic target; and wherein the second enzymatic target comprises a specific cleavage site of a second enzyme.

Abstract: The present invention provides partially fluorescent nanoparticles and methods of making and using the partially fluorescent nanoparticle having a nanoparticle with a matrix and a fluorescent dye dispersed in or about the matrix, wherein at least a portion of the fluorescent dye has been anisotropically bleached.

Abstract: The present invention includes a method and system for enhancing the signal-to-noise ratio in emission detection comprising: selecting a probe capable of at least one of fluorescence, phosphorescence, or delayed fluorescence in or about a sample that comprises interfering background signal; and exposing the probe to one or more controllable bursts, each burst comprising two or more pulses, wherein the one or more controllable bursts of high repetition energy pulses enhance the signal from the probe above that of the background signal.

Abstract: The present invention includes compositions and methods for fluorescence-based multiplex probe to simultaneously detect one or more enzymatic activities comprising: a first enzymatic target having a first end and a second end, wherein the first end of the first enzymatic target is attached to a central body and the second end of the first enzymatic target is attached to a first fluorophore; a second enzymatic target having a first end and a second end, wherein the first end of the second enzymatic target is attached to the central body and the second end of the second enzymatic target is attached to a third fluorophore; wherein the central body comprises at least one second fluorophore; wherein the first enzymatic target comprises a specific cleavage site of a first enzyme that cleaves the first enzymatic target; and wherein the second enzymatic target comprises a specific cleavage site of a second enzyme.

Abstract: The present invention includes methods for ratiometric detection of analytes by surface plasmon coupled emission detection that includes disposing a target on the metal layer of a surface plasmon resonance detection system; coupling a first analyte to a first fluorescent dye and a second analyte to a second fluorescent dye; contacting the first and second analytes to the target on the surface plasmon resonance detection system; and measuring the intensity of a first and a second surface plasmon resonance enhanced fluorescence emission ring, wherein the first and second rings, respectively, quantitatively represents the amount of first and second analyte within 50 nanometers of the metal surface.

Abstract: The present invention provides partially fluorescent nanoparticles and methods of making and using the partially fluorescent nanoparticle having a nanoparticle with a matrix and a fluorescent dye dispersed in or about the matrix, wherein at least a portion of the fluorescent dye has been anisotropically bleached.

Abstract: The present invention includes a microscope and a method for using the microscope for single molecule with reduced photobleaching of a fluorophore (20) that includes a light translucent material (16); a metal layer (18) disposed on the light translucent material (16); a medium (15) disposed on the metal layer (18), the medium (15) having one or more fluorophores (20) capable of binding a target analyte (e.g.

Abstract: The present invention describes the development of thin film calibration strips for microscopy/spectroscopy systems and a simple method/routine to conduct instrument calibration using partially (uniaxially) oriented strip to calibrate microscopy system without the prior knowledge of exact polarization of the strip. The invention describes results from studies including a styryl derivative (LDS 798) embedded in poly(vinyl alcohol) (PVA) film. These films were progressively stretched up to 8 folds. Vertical and horizontal components of absorptions and fluorescence were measured and dichroic ratios were determined for different film stretching ratios. The stretched films have high polarization values for isotropic excitation. The isotropic and stretched PVA films doped with LDS 798 can be used as etalons in near infra red (NIR) spectroscopic measurements.

Abstract: The present invention includes methods for ratiometric detection of analytes by surface plasmon coupled emission detection that includes disposing a target on the metal layer of a surface plasmon resonance detection system; coupling a first analyte to a first fluorescent dye and a second analyte to a second fluorescent dye; contacting the first and second analytes to the target on the surface plasmon resonance detection system; and measuring the intensity of a first and a second surface plasmon resonance enhanced fluorescence emission ring, wherein the first and second rings, respectively, quantitatively represents the amount of first and second analyte within 50 nanometers of the metal surface.

Abstract: The present invention includes a microscope and a method for using the microscope for single molecule with reduced photobleaching of a fluorophore (20) that includes a light translucent material (16); a metal layer (18) disposed on the light translucent material (16); a medium (15) disposed on the metal layer (18), the medium (15) having one or more fluorophores (20) capable of binding a target analyte (e.g.

Abstract: Methods and apparatus for fluorescence detection which can increase sensitivity by as much as 20 to 1000-fold are described. This method can preferably also decrease the contribution of sample autofluorescence to the detected signal. The method uses coupling of excited fluorophores with the surface plasmon resonance present in thin conductive films, for example silver, gold, aluminum, copper, or the like. The phenomenon of surface plasmon-coupled emission (SPCE) occurs for fluorophores in a volume adjacent to the conductive layer. This interaction is independent of the mode of excitation, that is, does not require evanescent wave or surface-plasmon excitation. However, such modes of excitation can be advantageous. SPCE can occur over a narrow angular distribution, converting normally isotropic emission into easily collected directional emission.

Abstract: Described is a new approach to fluorescence sensing based on a mixture of fluorophores, one of which is sensitive to the desired analyte. If a long lifetime analyte-insensitive fluorophore is mixed with a short lifetime analyte-sensitive fluorophore, the modulation of the emission at conveniently low frequencies becomes equal to the fractional fluorescence intensity of the sensing fluorophore. Under these conditions the modulation can be used to determine the analyte concentration. This can be used with any fluorophore which changes intensity in response to analyte, and does not require the sensing fluorophore to display a change in lifetime. The feasibility of modulation-based sensing was demonstrated using mixtures of 6-carboxyfluorescein and [Ru2,2′(bipyridyl)3]2+ as a pH sensor and of the calcium probe Fluo-3 and [Ru2,2′(bipyridyl)3]2+ as a calcium sensor.

Abstract: The steady state and time resolved luminescence spectral properties of two types of novel CdS nanoparticles and nanoparticles are described. CdS nanoparticles formed in the presence of an amine-terminated dendrimer show blue emission. The emission wavelength of these nanoparticles depended on the excitation wavelength. The CdS/dendrimer nanoparticles display polarized emission with the anisotropy rising progressively from 340 to 420 nm excitation, reaching a maximal anisotropy value in excess of 0.3. A new constant positive polarized emission from luminescent nanoparticles is also described. Polyphosphate-stabilized CdS nanoparticles are described that display a longer wavelength red emission maximum than bulk CdS and display a zero anisotropy for all excitation wavelengths. Both nanoparticles display strongly heterogeneous intensity decays with mean decay times of 93 ns and 10 &mgr;s for the blue and red emitting particles, respectively.

Abstract: The present invention relates to the determination of the presence or concentration of an analyte in a sample by visual or electronic element, using polarization based sensing techniques (14) employing fluorescent sensing (11) and reference molecules (10).

Abstract: A method of measuring an analyte present in animal (e.g., human) tissue or fluids such as blood or plasma. The analyte is multi-photon excitable (e.g., two-photon excitable) at a first wavelength at which the animal tissue is substantially non-absorbing. The analyte fluoresces at a second wavelength upon being excited at the first wavelength. The animal tissue is irradiated with radiation at the first wavelength so as to excite the analyte through absorption by the analyte of two or more photons of the radiation at the first wavelength. Excitation of the analyte results in a fluorescent emission from the analyte of radiation at the second wavelength. The emission at the second wavelength is detected, and the concentration of analyte determined based on the detected emission.

Abstract: A method and apparatus for detecting the change in phase angle and/or modulation of emitted fluorescence of a fluorophore excited by modulated light from a laser diode. The light is both monochromatic and coherent, and can contain harmonic frequency components. The laser diode can be used in frequency-domain or phase-modulation measurements of fluorescence, using either phase or modulation techniques. The present invention is an improvement of the prior use of a frequency-doubled, cavity-dumped, dye laser in fluorometers. The invention provides an inexpensive light excitation source that is small in size, easily manageable, allows for short measurement times, and has lower power requirements.