Abstract: Briefly, in accordance with one embodiment of the invention, the intensity of the signals from surface enhanced Raman spectroscopy may be increased by using lithium chloride as an enhancer to activate a metallic structure used for surface enhanced Raman spectroscopy. The increased signal intensity may allow surface enhanced Raman spectroscopy to be utilized to detect individual analytes such as nucleotides, for example in DNA sequencing without requiring a dye or radioactive label.

Abstract: The methods, systems 400 and apparatus disclosed herein concern metal 150 impregnated porous substrates 110, 210. Certain embodiments of the invention concern methods for producing metal-coated porous silicon substrates 110, 210 that exhibit greatly improved uniformity and depth of penetration of metal 150 deposition. The increased uniformity and depth allow improved and more reproducible Raman detection of analytes. In exemplary embodiments of the invention, the methods may comprise oxidation of porous silicon 110, immersion in a metal salt solution 130, drying and thermal decomposition of the metal salt 140 to form a metal deposit 150. In other exemplary embodiments of the invention, the methods may comprise microfluidic impregnation of porous silicon substrates 210 with one or more metal salt solutions 130. Other embodiments of the invention concern apparatus and/or systems 400 for Raman detection of analytes, comprising metal-coated porous silicon substrates 110, 210 prepared by the disclosed methods.

Abstract: The disclosed methods and apparatus concern Raman spectroscopy using metal coated nanocrystalline porous silicon substrates. Porous silicon substrates may be formed by anodic etching in dilute hydrofluoric acid. A thin coating of a Raman active metal, such as gold or silver, may be coated onto the porous silicon by cathodic electromigration or any known technique. In certain alternatives, the metal coated porous silicon substrate comprises a plasma-oxidized, dip and decomposed porous silicon substrate. The metal-coated substrate provides an extensive, metal rich environment for SERS, SERRS, hyper-Raman and/or CARS Raman spectroscopy. In certain alternatives, metal nanoparticles may be added to the metal-coated substrate to further enhance the Raman signals. Raman spectroscopy may be used to detect, identify and/or quantify a wide variety of analytes, using the disclosed methods and apparatus.

Abstract: The methods, apparatus and compositions disclosed herein concern the detection, identification and/or sequencing of biomolecules, such as nucleic acids or proteins. In certain embodiments of the invention, coded probes comprising a probe molecule attached to one or more nano-barcodes may be allowed to bind to one or more target molecules. After binding and separation from unbound coded probes, the bound coded probes may be aligned on a surface and analyzed by scanning probe microscopy. The nano-barcodes may be any molecule or complex that is distinguishable by SPM, such as carbon nanotubes, fullerenes, submicrometer metallic barcodes, nanoparticles or quantum dots. Where the probes are oligonucleotides, adjacent coded probes hybridized to a target nucleic acid may be ligated together before alignment and SPM analysis. Compositions comprising coded probes are also disclosed herein. Systems for biomolecule analysis may comprise an SPM instrument and at least one coded probe attached to a surface.

Abstract: The methods and apparatus disclosed herein concern nucleic acid sequencing by enhanced Raman spectroscopy. In certain embodiments of the invention, nucleotides are covalently attached to Raman labels before incorporation into a nucleic acid. In other embodiments, unlabeled nucleic acids are used. Exonuclease treatment of the nucleic acid results in the release of labeled or unlabeled nucleotides that are detected by Raman spectroscopy. In alternative embodiments of the invention, nucleotides released from a nucleic acid by exonuclease treatment are covalently cross-linked to nanoparticles and detected by surface enhanced Raman spectroscopy (SERS), surface enhanced resonance Raman spectroscopy (SERRS) and/or coherent anti-Stokes Raman spectroscopy (CARS). Other embodiments of the invention concern apparatus for nucleic acid sequencing.

Abstract: The present methods and apparatus concern the detection and/or identification of target analytes using probe molecules. In various embodiments of the invention, the probes or analytes are attached to one or more cantilevers. Binding of a probe to an analyte results in deflection of the cantilever, detected by a detection unit. A counterbalancing force may be applied to restore the cantilever to its original position. The counterbalancing force may be magnetic, electrical or radiative. The detection unit and the mechanism generating the counterbalancing force may be operably coupled to an information processing and control unit, such as a computer. The computer may regulate a feedback loop that maintains the cantilever in a fixed position by balancing the deflecting force and the counterbalancing force. The concentration of analytes in a sample may be determined from the magnitude of the counterbalancing force required to maintain the cantilever in a fixed position.

Abstract: The methods and apparatus disclosed herein concern nucleic acid characterization by enhanced Raman spectroscopy. In certain embodiments of the invention, exonuclease treatment of the nucleic acids results in the release of nucleotides. The nucleotides may pass from a reaction chamber through a microfluidic channel and enter a nanochannel or microchannel. The nanochannel or microchannel may be packed with nanoparticle aggregates containing hot spots for Raman detection. As the nucleotides pass through the nanoparticle hot spots, they may be detected by Raman spectroscopy. Identification of the sequence of nucleotides released from the nucleic acid is used to characterize the nucleic acid, for example by sequencing or identifying the nucleic acid. Other embodiments of the invention concern apparatus for nucleic acid sequencing.

Abstract: The methods, apparatus and compositions disclosed herein concern the detection, identification and/or sequencing of biomolecules, such as nucleic acids or proteins. In certain embodiments of the invention, coded probes comprising a probe molecule attached to one or more nanobarcodes may be allowed to bind to one or more target molecules. After binding and separation from unbound coded probes, the bound coded probes may be aligned on a surface and analyzed by scanning probe microscopy. The nanobarcodes may be any molecule or complex that is distinguishable by SPM, such as carbon nanotubes, fullerenes, submicrometer metallic barcodes, nanoparticles or quantum dots. Where the probes are oligonucleotides, adjacent coded probes hybridized to a target nucleic acid may be ligated together before alignment and SPM analysis. Compositions comprising coded probes are also disclosed herein. Systems for biomolecule analysis may comprise an SPM instrument and at least one coded probe attached to a surface.

Abstract: The present methods and apparatus concern the detection and/or identification of target analytes using probe molecules. In various embodiments of the invention, the probes or analytes are attached to one or more cantilevers. Binding of a probe to an analyte results in deflection of the cantilever, detected by a detection unit. A counterbalancing force may be applied to restore the cantilever to its original position. The counterbalancing force may be magnetic, electrical or radiative. The detection unit and the mechanism generating the counterbalancing force may be operably coupled to an information processing and control unit, such as a computer. The computer may regulate a feedback loop that maintains the cantilever in a fixed position by balancing the deflecting force and the counterbalancing force. The concentration of analytes in a sample may be determined from the magnitude of the counterbalancing force required to maintain the cantilever in a fixed position.

Abstract: Microfluidic devices with porous membranes for molecular sieving, metering, and separation of analyte fluids. In one aspect, a microfluidic device includes a substrate having input and output microfluidic channel sections separated by a porous membrane formed integral to the substrate. In another aspect, the porous membrane may comprise a thin membrane that is sandwiched between upper and lower substrate members. The microfluidic device may include one or a plurality of porous membranes. In one embodiment, a plurality of porous membranes having increasingly smaller pores are disposed along portions of a microfluidic channel. In another embodiment, a cascading series of upper and lower channels are employed, wherein each upper/lower channel interface is separated by a respective porous membrane. In another aspect, a porous membrane is rotatably coupled to a substrate within a microfluidic channel via a MEMS actuator to enable the porous membrane to be positioned in filtering and pass-through positions.

Abstract: Microfluidic apparatus including integrated porous substrate/sensors that may be used for detecting targeted biological and chemical molecules and compounds. In one aspect, upper and lower microfluidic channels are defined in respective halves of a substrate, which are sandwiched around a porous membrane upon assembly. In another aspect, the upper and lower channels are formed such that a portion of the lower channel passes beneath a portion of the upper channel to form a cross-channel area, wherein the membrane is disposed between the two channels. In various embodiments, one or more porous membranes are disposed proximate to corresponding cross-channel areas defined by one or more upper and lower channels. The porous membrane may also have sensing characteristics, such that it produces a change in an optical and/or electronic characteristic.

Abstract: The methods and apparatus 300 disclosed herein concern Raman spectroscopy using metal coated nanocrystalline porous silicon substrates 240, 340. In certain embodiments of the invention, porous silicon substrates 110, 210 may be formed by anodic etching in dilute hydrofluoric acid 150. A thin coating of a Raman active metal, such as gold or silver, may be coated onto the porous silicon 110, 210 by cathodic electromigration or any known technique. The metal-coated substrate 240, 340 provides an extensive, metal rich environment for SERS, SERRS, hyper-Raman and/or CARS Raman spectroscopy. In certain embodiments of the invention, metal nanoparticles may be added to the metal-coated substrate 240, 340 to further enhance the Raman signals. Raman spectroscopy may be used to detect, identify and/or quantify a wide variety of analytes, using the disclosed methods and apparatus 300.

Abstract: The present methods and apparatus 100 concern nucleic acid 214 sequencing by incorporation of nucleotides 218 into nucleic acid strands 220. The incorporation of nucleotides 218 is detected by changes in the mass and/or surface stress of the structure 116, 212. In some embodiments of the invention, the structure 116, 212 comprises one or more nanoscale or microscale cantilevers. In certain embodiments of the invention, each different type of nucleotide 218 is distinguishably labeled with a bulky group and each incorporated nucleotide 218 is identified by the changes in mass and/or surface stress of the structure 116, 212 upon incorporation of the nucleotide 218. In alternative embodiments of the invention only one type of nucleotide 218 is exposed at a time to the nucleic acids 214, 220. Changes in the properties of the structure 116, 212 may be detected by a variety of methods, such as piezoelectric detection, shifts in resonant frequency of the structure 116, 212, and/or position sensitive photodetection.

Abstract: The methods and apparatus disclosed herein concern nucleic acid sequencing by enhanced Raman spectroscopy. In certain embodiments of the invention, exonuclease treatment of the nucleic acids 109 results in the release of nucleotides 110. The nucleotides may pass from a reaction chamber 101 through a microfluidic channel 102 and enter a nanochannel or microchannel 103. The nanochannel or microchannel 103 may be packed with nanoparticle 111 aggregates containing hot spots for Raman detection. As the nucleotides 110 pass through the nanoparticle 111 hot spots, they may be detected by surface enhanced Raman spectroscopy (SERS), surface enhanced resonance Raman spectroscopy (SERRS) and/or coherent anti-Stokes Raman spectroscopy (CARS). Identification of the sequence of nucleotides 110 released from the nucleic acid 109 provides the nucleic acid sequence. Other embodiments of the invention concern apparatus 100 for nucleic acid sequencing.

Abstract: The methods and apparatus disclosed herein concern nucleic acid sequencing by enhanced Raman spectroscopy. In certain embodiments of the invention, nucleotides are covalently attached to Raman labels before incorporation into a nucleic acid 13. Exonuclease 15 treatment of the labeled nucleic acid 13 results in the release of labeled nucleotides 16, 130, which are detected by Raman spectroscopy. In alternative embodiments of the invention, nucleotides 16, 130 released from a nucleic acid 13 by exonuclease 15 treatment are covalently cross-linked to silver or gold nanoparticles 140 and detected by surface enhanced Raman spectroscopy (SERS), surface enhanced resonance Raman spectroscopy (SERRS) and/or coherent anti-Stokes Raman spectroscopy (CARS). Other embodiments of the invention concern apparatus 10, 100, 210 for nucleic acid sequencing.

Abstract: A biological sensor which includes: a porous semiconductor structure comprising a central layer interposed between upper and lower layers, each of the upper and lower layers including strata of alternating porosity; and one or more probes coupled to the porous semiconductor structure, the one or more probes binding to a target molecule, whereby a detectable change occurs in a refractive index of the biological sensor upon binding of the one or more probes to the target molecule. Methods of making the biological sensor and methods of using the same are disclosed, as is a detection device which includes such a biological sensor.