Rta Eas & Pittcon 2010 Sers Featured Talks
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Rta Eas & Pittcon 2010 Sers Featured Talks Rta Eas & Pittcon 2010 Sers Featured Talks Presentation Transcript

  • Highly Sensitive SER-Active Sol-Gel Substrates RTA SERS Team: Stuart Farquharson (CEO), Frank Inscore (R&D Director), Atanu Sengupta & Chetan Shende (Senior Research Chemists) • Substrates • Applications • Chemical Agents in Water • Pesticides/Adulterants in Food • Illicit Drugs in Saliva • Proteomics • Devices Booth 2825www.rta.biz Providing Chemical Information When & Where You Need It
  • The SERS Promise (if) • Enable Raman Spectroscopy to provide routine sub part per million chemical analysisThe SERS Delivery (then) • Extend Raman’s usefulness to a vast number of trace chemical analysesBut… • Can a SERS-active medium meet the requirements of an analytical instrument? Providing Chemical Information When & Where You Need It
  • Performance Criteria1. Sensitivity (LOD, LOQ, LMC)2. Linearity3. Selectivity4. Reproducibility5. Shelf-Life6. Usable Media7. Sample Requirements: gas, liq, sol8. Production Costs
  • Surface-enhanced Raman Spectroscopy When a molecule is within a plasmon field, the efficiency of Raman scattering can increase by 1 million times! Sub part-per million detection becomes possible. Single Molecule Detection: Chemical contribution requires 1012 -1014 can provide additional 103 enhancement
  • SERS-Active Media Traditional: • Electrochemically Roughened Electrodes • Metal Colloidal Hydrosols • Metal Islands or Nanoparticles on Solid Supports • Metal Coated Surface Structures • Self-Assembled Monolayers (SAMs) Recent: • Metal-Doped Porous Media • Periodic Apertures in Metals • Metal Shells • Fiber Optic Tips Providing Chemical Information When & Where You Need It
  • Electrochemically Roughened Electrodes Features: 50-250 nm wide, Pentaamine(pyridine)Osmium 75-200 nm high Farquharson, et al (Weaver), JACS, 105, 3350 (1983) Providing Chemical Information When & Where You Need It
  • Electrochemically Roughened Electrodes Limitation: Identical ORCs 735 cm-1 do not produce -1.7Vsce 10 sec Identical Surfaces.Adenine in an Electrolytic Flow Cell Farquharson et al, SPIE, 3533, 1998 Providing Chemical Information When & Where You Need It
  • Silver and gold colloids in solution10-25 nm Silver Colloid 30-50 nm Silver ColloidLee & Meisel, J Phys Chem, Aggregates (spermine) 86, 3391 (1986) Graham, Smith et al, Anal Chem, 69, 4703 (1997) Providing Chemical Information When & Where You Need It
  • Vapor Deposition on Glass & Sol-Gels 1 micron 20 nm Silver film 5 microns Bis Pyridyl Ethene Gold Film on Sol-Gel Ruthenium Tris bypyridine Providing Chemical Information When & Where You Need It
  • Vapor Deposition on Spheres 10 microns Silver on polystyrene, silica, titania…Vo-Dinh, Anal Chem, 56, 1677 (1984); ibid, 87, 59 (1987) CWA Dosimeter Providing Chemical Information When & Where You Need It
  • Vapor Deposition…on nanospheres200 nm Ag on 390 nm spheres Glucose on 1-decanethiol coating Haynes et al (Van Duyne), J Raman Spec, 36, 471 (2005) Providing Chemical Information When & Where You Need It
  • Vapor Deposition Shapes Benzenethiol on Truncated Pyramids Haes & Van Duyne JACS, 124, 10596 (2002) Providing Chemical Information When & Where You Need It
  • Metal coated spheres - Nanoshells Silver on silica spheres p-mercaptoaniline Jackson & Halas PNAS, 101, 17930 (2004) Providing Chemical Information When & Where You Need It
  • Periodic Apertures 300 nm Gold film200 nm Silver film On inverted 1 Gold film 150 nm hole micron pyramidal ~250 nm hole 900 nm spacing pitsGhaemi et al. Phys Rev ~450 nm spacing Rowlen (web site) Perney et al, Optics B, 58, 6779 (1998) Express, 14, 847 (2006) Providing Chemical Information When & Where You Need It
  • Traditional SERS-Active MediaMajor Limitations: • Electrodes - Irreproducible Roughness • Colloids - Unstable Media (e.g. pH) • Vapor Coated Spheres – no substrate-to-substrate consistency • Specific Structures - less enhancement • Stringent Sample Requirements (e.g. solvent) • Expensive Devices • Irreversible (single measurements) Providing Chemical Information When & Where You Need It
  • Which do you want: Sensitivity or Reproducibility? 1 square micron = 12.6 silver particles Laser spot (325 micron diameter) = 83,000 square microns i.e. contains 1.04 million silver particles Or the equivalent of 1 perfect hot spot generating 1012 enhancement 10 microns SERS: silver particles in sol-gel Providing Chemical Information When & Where You Need It
  • SERS-Active Substrates benzenethiol 10-3M 10-5M 10-8M (~10 ppb) Providing Chemical Information When & Where You Need It
  • RTA SERS Sampling Systems 2001: Simple SERS Sample Vials Molecules Sol-Gel Matrix Raman in Solution Scattering 2001 Laser Adsorbed Molecules Metal Particle 2004: SERS-Active Capillary 1 10 More suited to extract and pre-concentrate Providing Chemical Information When & Where You Need It
  • Challenge: specific, fast, sensitive• Specificity – identify chemical agents & hydrolysis products • No False Positives!• Speed – monitor poisoned water (batch & continuous) • 10 min or less• Sensitivity – Requirements to protect • CN – 6 mg/L (6 ppm) • HD - 100 microg/L (100 ppb)  TDG • Nerve - 5 microg/L (5 ppb)  MPA Part-per-billion is challenging! Providing Chemical Information When & Where You Need It
  • Analysis: CWA Hydrolysis Products H2 OHCN H3 O+ + CN- H2 O TDG 2 HCl + HD S S Cl Cl HO OH O O H2 O DIASH + P O H2 O N EMPA ethanol + O OH HS P VX P N O OH MPA O S HO H2 O EtOH + EA2192 DIASH + MPA P N O S O N H2 O O N H2 O O N GA P HCN + EDMAPA ethanol + O P P DMAPA C N O OH O OH H2 O O H2 O O HF + IMPA 2-propanol + MPA GB P P O F O OH H2 O H2 O GD O HF + O PMPA 2-pinacolyl + MPA P P O F O OH H2 O H2 O O O CMPA cyclohexanol + MPA GF HF + P P O F O OH Providing Chemical Information When & Where You Need It
  • SERS: 10 parts-per-billion MPA TDG CN Providing Chemical Information When & Where You Need It
  • Parker-Haniffin Intraflow Sample System Providing Chemical Information When & Where You Need It
  • Measurements using NeSSI 10 ppb CN- 100 ppb TDG 50 ppb 75 ppb MPA Sunset Yellow Spiked Water “EWS-2008-002”from Kensico, NY water reservoir Providing Chemical Information When & Where You Need It
  • User Interface Providing Chemical Information When & Where You Need It
  • Challenge: minimize pesticide contamination • Need pesticides to meet food demand (US imports 33 million tons of fruit) • 2.8% of imports exceed guidelines • Only 1 % is tested Shende et al SPIE, 5587, ??? (2005) Providing Chemical Information When & Where You Need It
  • Challenge: Detect Residues in Food & Feed Residues in Food Baby Food Feed DDT carbaryl malathion chlorpyrifos-methyl chlorpyrifos-methyl chlorpyrifos-methyl malathion malathion chlorpyrifos endosulfan permethrin methoxychlor dieldrin ethylenethiourea tribufos chlorpyrifos endosulfan pirimiphos-methyl chlorpropham chlorpyrifos diazon permethrin iprodione ethoxyquin iprodione thiabendazole ethion chlordane dimethoate gardona Requirements 10 ppb to 10 ppm. Providing Chemical Information When & Where You Need It
  • Analysis: methyl parathion Normal Raman Normal Raman Surface-Enhanced Raman Surface-Enhanced Raman Providing Chemical Information When & Where You Need It
  • Analysis: Chlorpyrifos Normal Raman Normal Raman Surface-Enhanced Raman Surface-Enhanced Raman Providing Chemical Information When & Where You Need It
  • Swab Test: carbaryl on an apple 1 Spray 2 Swab 3 Extract 4 Measure Providing Chemical Information When & Where You Need It
  • Sensitivity:10 ppb75 mW of 785 nm1 min Providing Chemical Information When & Where You Need It
  • SERS of Melamine 0.5 PPM (X20) Glass Luminescence 5 PPM Simple SERS Pure Melamine Sample Vial Providing Chemical Information When & Where You Need It
  • SERS of Melamine0.5 PPM in Solvent (X20) Glass Luminescence 5 PPM in Solvent 250 PPM extracted Simple SERS from Baby Formula Sample Vial Providing Chemical Information When & Where You Need It
  • Challenge: determine overdose drug • 1/3rd of all ER cases are drug overdose related • 50% are due to cocaine • Cocaine overdose symptoms are similar to many other ER cases, particularly heart attack • A 5-min diagnosis would be invaluable to select treatment • Current analysis of drugs use 10-20 ml blood • Centrifugation to remove red blood cells • Extraction using organic solvents • Separation using chromatography • Detection with UV or Mass Spec • Standards are needed to ensure measurement accuracy • These methods are labor intensive, time consuming, • Analysis time is typically 30-60 min. Providing Chemical Information When & Where You Need It
  • Solution: Saliva analysis by surface-enhanced Raman• Drug metabolites represented in saliva • Usually 10-50% of blood plasma (1-10 microg/mL)• Non-invasive (no needles)• Saliva is 99.5% water • Interfering physiological chemicals 100X less than blood• But Currently analyses require 10-20 cc• Raman – chemical specificity• SERS – increased sensitivity (goal=1 mg/L, 1ppm)• Simple SERS Syringe • Small sample volumes – 100 microL (few drops) • Rapid analysis time (1-2 min) Shende et al SPIE, 6007, ??? (2005) Providing Chemical Information When & Where You Need It
  • Analysis: cocaine Normal Raman SERS Wavenumbers 300 microliter sample (6 drops) All 0.33 mg/mL Providing Chemical Information When & Where You Need It
  • Drug Detection on aUniversal SERS Chip 2 inches Benzoylecgonine Methanol Cocaine300 microliter sample (6 drops) All ~50 ppm Providing Chemical Information When & Where You Need It
  • Simple SERS Sample Vials: Uniform CoatingsSignificant improvement in RSD using new high-speed roller Providing Chemical Information When & Where You Need It
  • Chemical Residue Detector A Portable, Field usable SERS Analyzer5 Pounds 10” 5” 3.4” Providing Chemical Information When & Where You Need It
  • Chemical Residue Detector 1-10 ppm TNT Melamine Chlorpyrifos-Methyl Methyl Phosphonic Acid Aspirin Aspargine Raman Shift, cm-1
  • Chemical Residue Detector
  • Proteomics (Amino Acid Sequencing) Providing Chemical Information When & Where You Need It
  • 96-Well SERS-Active PlateWe develop SERS Sample Systems for You Booth 2825
  • Challenge: regulate drug dosage• Chemotherapy drugs also kill non-cancer cells• Dosage is critical• No clinical trials to establish statistical based dosage• Current analysis of drugs and metabolites use 10-20 ml blood • Centrifugation to remove red blood cells • Extraction using organic solvents • Separation using chromatography • Detection with UV or Mass Spec• Standards are needed to ensure measurement accuracy• These methods are labor intensive, time consuming, unsafe• Consequently, measurements made on an “as needed” basis Providing Chemical Information When & Where You Need It
  • Background: 5-Fluorouracil (5-FU) O H 4 F • One of most widely used chemotherapy drugs 5 N3 2 6 • Colorectal carcinoma O 1 N H • Structure similar to uracil H • Metabolites incorporate into RNA and DNA • Wide genetic-based variation in metabolism, 15-80% inactive • Half life is 5-20 minutes •Various dosage regimens based on type and phase of cancer • Concentrations in saliva similar to blood plasma Farquharson et alJ Raman Spec, 36, 208 (2005), Vib Spec, 38, 29 (2005) Providing Chemical Information When & Where You Need It
  • Analysis: 5-Fluorouracil Normal Raman Surface-Enhanced Raman Providing Chemical Information When & Where You Need It
  • Simple Separation Devices 5FU A & 5FUH2 SERS-Active Lab-on-a-Chip Sample Injection 5FdUrd Syringe B C A Leucovorin B CSimulated analysis of 600 800 1000 1200 1400 1600 Wavenumbers (cm-1)5-FU in saliva Providing Chemical Information When & Where You Need It
  • Challenge: sensitivity, speed, specificity• Sensitivity – protect exposed personnel • Anthrax LD50 estimated at ~10,000 spores (100 nanograms) • Goal is closer to 100 spores/cm2• Speed – need to map area (target 1 min per spot)• Specificity – extreme minimum in false positives• Current methods: • DNA or RNA enumeration: (Culture growth - 24 hours) or Polymerase Chain Reactions (PCR, >4 hours) • test kits (limited shelf life, very high false positive rate) Providing Chemical Information When & Where You Need It
  • Approach: measure anthrax signature - CaDPA Core Wall Cortex (proteins-cysteine, (peptidoglycan) Ca dipicolinate) DNA 2- Ribosomes O O Ca 2+ O C N C O Spore Coat Exosporium CaDPAFarquharson, Maksymiuk & Inscore Appl Spec, 58, 351 (2004) Providing Chemical Information When & Where You Need It
  • SERS and RS of dipicolinic acid (DPA) 10 mg/L SERS Sat’d KOH sol DPA by RamanSERS: 150 mW, 1-min, NR:450 mW, 5-min Providing Chemical Information When & Where You Need It
  • Extraction & Identification of DPA in 2-min! 0. Dried 2200 spores from 1 microliter 1. Added 10 micoliters of SporeDestroyer (1-min digestion) 2. Suck 1 microliter into 3. Measure SERS of DPASER-active capillary (10-sec) (10% = 220 pg/microliter) (10-sec placement, 30-sec scan) Providing Chemical Information When & Where You Need It
  • SERS: 220 Spores 220 pg/microL DPA 100 pg/microL (ppb) reference spectrum Internal Reference 1000 pg/microL = 1 ppm, no big deal Providing Chemical Information When & Where You Need It