# US 7,608,305 B2 · Methods for uniform metal impregnation into a nanoporous material > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 7,608,305 B2 - Document ID: US7608305B2 - Status: Granted - Kind: B2 - Application number: 11/436,489 - Filed: 2006-05-18 - Published: 2007-05-24 - Granted: 2009-10-27 - Earliest claimed: 2003-02-18 - Assignees: Intel Corporation - Inventors: Selena Chan; Sunghoon Kwon; Narayan Sundararajan - Web page: https://patentgrep.com/patent/US7608305B2 ## CPC - G01N 21/658: {enhancement Raman, e.g. surface plasmons} - B01D 67/0062: {by micromachining techniques, e.g. using masking and etching steps, photolithography} - B01D 67/0086: {Mechanical after-treatment} - B01D 67/0088: {Physical treatment with compounds, e.g. swelling, coating or impregnation} - B01D 71/0213: {Silicon} - B01D 71/0215: {Silicon carbide; Silicon nitride; Silicon oxycarbide} - B82Y 30/00: Nanotechnology for materials or surface science, e.g. nanocomposites - C12Q 1/6825: Nucleic acid detection involving sensors - G01N 21/65: Raman scattering - B82Y 15/00: Nanotechnology for interacting, sensing or actuating, e.g. quantum dots as markers in protein assays or molecular motors - G01J 3/44: Raman spectrometry; Scattering spectrometry {; Fluorescence spectrometry} - G01N 2021/6439: {with indicators, stains, dyes, tags, labels, marks} - G01N 2021/655: {Stimulated Raman} - G01N 2021/656: {Raman microprobe} - G01N: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES (measuring or testing apparatus or processes other than immunoassay, involving enzymes or microorganisms C12M, C12Q) - B01D: SEPARATION (separating solids from solids by wet methods B03B, B03D; by pneumatic jigs or tables B03B; by other dry methods B07; magnetic or electrostatic separation of solid materials from solid materials or fluids, separation by high-voltage electric fields B03C; centrifuges, vortex apparatus B04; presses per se for squeezing-out liquid from liquid-containing material B30B9/02; treatment of water C02F, e.g. softening by ion-exchange C02F1/42; {arrangements of air intake cleaners in gas turbine plants F02C7/05} ; arrangements or mounting of filters in air-conditioning, air-humidification or ventilation F24F13/28) - B82Y: SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES - C12Q: MEASURING OR TESTING PROCESSES INVOLVING ENZYMES, NUCLEIC ACIDS OR MICROORGANISMS (immunoassay G01N33/53); COMPOSITIONS OR TEST PAPERS THEREFOR; PROCESSES OF PREPARING SUCH COMPOSITIONS; CONDITION-RESPONSIVE CONTROL IN MICROBIOLOGICAL OR ENZYMOLOGICAL PROCESSES - G01J: MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT, POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRARED, VISIBLE OR ULTRAVIOLET LIGHT; COLORIMETRY; RADIATION PYROMETRY (light sources F21, H01J, H01K, H05B; investigating properties of materials by optical means G01N) ## 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. ## Claims ### Claim 1 A method comprising: a) obtaining a porous membrane; b) inserting the porous membrane into a microfluidic pathway between a solvent reservoir and a waste reservoir connected through cross-paths, wherein the porous membrane is placed between the cross-paths; c) introducing a metal salt solution into the porous membrane to form a metal coated porous membrane; and d) incorporating the metal-coated porous membrane in a system for analysis and/or separation of polymer molecules. ### Claim 2 (depends on 1) The method of claim 1, wherein the porous membrane is a porous silicon membrane, a porous polysilicon membrane, a porous aluminum membrane, a porous alumina membrane or a porous metal grid. ### Claim 3 (depends on 1) The method of claim 1, wherein the porous membrane is a porous silicon membrane. ### Claim 4 (depends on 1) The method of claim 1, further comprising electropolishing the porous membrane. ### Claim 5 (depends on 1) The method of claim 1, wherein two or more different metal salt solutions are introduced into the porous membrane. ### Claim 6 (depends on 1) The method of claim 1, wherein the metal-coated porous membrane comprises at least one Raman active metal selected from the group consisting of silver, gold, platinum, copper and aluminum. ### Claim 7 (depends on 1) The method of claim 1, further comprising incorporating the metal-coated porous membrane in a Raman detection system. ### Claim 8 (depends on 7) The method of claim 7, further comprising introducing a sample comprising a target molecule into the metal-coated porous membrane, exciting the target molecule with an excitatory light, and detecting a Raman signal by a Raman detector. ### Claim 9 (depends on 8) The method of claim 8, further comprising removing the sample from the metal-coated porous membrane. ### Claim 10 (depends on 8) The method of claim 8, wherein the method is configured to detect a single molecule. ### Claim 11 (depends on 10) The method of claim 10, wherein the single molecule is a single molecule of a nucleotide. ### Claim 12 (depends on 8) The method of claim 8, further comprising introducing a chemical enhancer to enhance the Raman signal.