摘要:
A method and apparatus with the sensitivity to detect and identify single target molecules through the localization of dual, fluorescently labeled probe molecules. This can be accomplished through specific attachment of the taget to a surface or in a two-dimensional (2D) flowing fluid sheet having approximate dimensions of 0.5 μm×100 μm×100 μm. A device using these methods would have 103–104 greater throughput than previous one-dimensional (1D) micro-stream devices having 1 μm3 interrogation volumes and would for the first time allow immuno- and DNA assays at ultra-low (femtomolar) concentrations to be performed in short time periods (˜10 minutes). The use of novel labels (such as metal or semiconductor nanoparticles) may be incorporated to further extend the sensitivity possibly into the attomolar range.
摘要:
Surface-Enhanced Raman Spectroscopy (SERS) is a vibrational spectroscopic technique that utilizes metal surfaces to provide enhanced signals of several orders of magnitude. When molecules of interest are attached to designed metal nanoparticles, a SERS signal is attainable with single molecule detection limits. This provides an ultrasensitive means of detecting the presence of molecules. By using selective chemistries, metal nanoparticles can be functionalized to provide a unique signal upon analyte binding. Moreover, by using measurement techniques, such as, ratiometric received SERS spectra, such metal nanoparticles can be used to monitor dynamic processes in addition to static binding events. Accordingly, such nanoparticles can be used as nanosensors for a wide range of chemicals in fluid, gaseous and solid form, environmental sensors for pH, ion concentration, temperature, etc., and biological sensors for proteins, DNA, RNA, etc.
摘要:
A surface-enhanced Raman scattering method and apparatus to sequence polymeric biomolecules such as DNA, RNA, or proteins is introduced. The method uses metallic nanostructures such as, for example, spherical or cylindrical Au or Ag nanoparticles having characteristic lengths of 10-100 nm which when illuminated with light of the appropriate wavelength produce resonant oscillations of the conduction electrons (plasmon resonance). Electric field enhancements of 30-1000 near the particle surface resulting from such oscillations increase Raman scattering cross-sections by about 106-1015 due to the E4 dependence of the Raman scattering, wherein the largest enhancements occur in the gap/junction between novel closely spaced structures as disclosed herein.
摘要:
Methods are provided for the determination of the concentration of biological levels of polyhydroxylated compounds, particularly glucose. The methods utilize an amplification system that is an analyte transducer immobilized in a polymeric matrix, where the system is implantable and biocompatible. Upon interrogation by an optical system, the amplification system produces a signal capable of detection external to the skin of the patient. Quantitation of the analyte of interest is achieved by measurement of the emitted signal.
摘要:
An implantable chemical sensor system for medical applications is described which permits selective recognition of an analyte using an expandable biocompatible sensor, such as a polymer, that undergoes a dimensional change in the presence of the analyte. The expandable polymer is incorporated into an electronic circuit component that changes its properties (e.g., frequency) when the polymer changes dimension. As the circuit changes its characteristics, an external interrogator transmits a signal transdermally to the transducer, and the concentration of the analyte is determined from the measured changes in the circuit. This invention may be used for minimally invasive monitoring of blood glucose levels in diabetic patients.
摘要:
The present invention provides formulae for fluorescent compounds that have a number of properties which make them uniquely suited for use in sensors of analytes such as saccharides. The advantageous fluorescent properties include favorable excitation wavelengths, emission wavelengths, fluorescence lifetimes, and photostability. Additional advantageous properties include enhanced aqueous solubility, as well as temperature and pH sensitivity. The compound comprises an aryl or a substituted phenyl botonic acid that acts as a substrate recognition component, a fluorescence switch component, and a fluorophore. Fluorescent compounds are described that are excited at wavelengths greater than 400 nm and emit at wavelengths greater than 450 nm, which is advantageous for optical transmission through skin. The fluorophore is typically selected from transition metal-ligand complexes and thiazine, oxazine, oxazone, or oxazine-one as well as anthracene compounds. The fluorescent compound can be immobilized in a glucose permeable biocompatible polymer matrix that is implantable below the skin.
摘要:
An analyte sensing fluorescent molecule that employs intramolecular electron transfer is designed to exhibit selected fluorescent properties in the presence of analytes such as saccharides. The selected fluorescent properties include excitation wavelength, emission wavelength, fluorescence lifetime, quantum yield, photostability, solubility, and temperature or pH sensitivity. The compound comprises an aryl or a substituted phenyl boronic acid that acts as a substrate recognition component, a fluorescence switch component, and a fluorophore. The fluorophore and switch component are selected such that the value of the free energy for electron transfer is less than about 3.0 kcal mol−1. Fluorescent compounds are described that are excited at wavelengths greater than 400 nm and emit at wavelengths greater than 450 nm, which is advantageous for optical transmission through skin. The fluorophore is typically selected from transition metal-ligand complexes and thiazine, oxazine, oxazone, or oxazine-one as well as anthracene compounds. The fluorescent compound can be immobilized in a glucose permeable biocompatible polymer matrix that is implantable below the skin.
摘要:
Fluorescent biosensor molecules, fluorescent biosensors and systems, as well as methods of making and using these biosensor molecules and systems are described. Embodiments of these biosensor molecules exhibit fluorescence emission at wavelengths greater than about 650 nm. Typical biosensor molecules include a fluorophore that includes an iminium ion, a linker moiety that includes a group that is an anilinic type of relationship to the fluorophore and a boronate substrate recognition/binding moiety, which binds glucose. The fluorescence molecules modulated by the presence or absence of polyhydroxylated analytes such as glucose. This property of these molecules of the invention, as well as their ability to emit fluorescent light at greater than about 650 nm, renders these biosensor molecules particularly well-suited for detecting and measuring in-vivo glucose concentrations.
摘要:
Methods are provided for the determination of the concentration of biological levels of polyhydroxylated compounds, particularly glucose. The methods utilize an amplification system that is an analyte transducer immobilized in a polymeric matrix, where the system is implantable and biocompatible. Upon interrogation by an optical system, the amplification system produces a signal capable of detection external to the skin of the patient. Quantitation of the analyte of interest is achieved by measurement of the emitted signal.
摘要:
An implantable chemical sensor system for medical applications is described which permits selective recognition of an analyte using an expandable biocompatible sensor, such as a polymer, that undergoes a dimensional change in the presence of the analyte. The expandable polymer is incorporated into an electronic circuit component that changes its properties (e.g., frequency) when the polymer changes dimension. As the circuit changes its characteristics, an external interrogator transmits a signal transdermally to the transducer, and the concentration of the analyte is determined from the measured changes in the circuit. This invention may be used for minimally invasive monitoring of blood glucose levels in diabetic patients.