Porous Silicon-Based Optical Microsensors for Volatile Organic Analytes: Effect of Surface Chemistry on Stability and Specificity

Details

• Personal Author:
  King BH ; Ruminski AM ; Sailor MJ ; Salonen J ; Snyder JL
• Description:
  Sensing of the volatile organic compounds (VOCs) isopropyl alcohol (IPA) and heptane in air using sub-millimeter porous silicon-based sensor elements is demonstrated in the concentration range 50-800 ppm. The sensor elements are prepared as one-dimensional photonic crystals (rugate filters) by programmed electrochemical etch of p++ silicon, and analyte sensing is achieved by measurement of the wavelength shift of the photonic resonance. The sensors are studied as a function of surface chemistry: ozone oxidation, thermal oxidation, hydrosilylation (1-dodecene), electrochemical methylation, reaction with dicholorodimethylsilane and thermal carbonization with acetylene. The thermally oxidized and the dichlorodimethylsilane-modified materials show the greatest stability under atmospheric conditions. Optical microsensors are prepared by attachment of the porous Si layer to the distal end of optical fibers. The acetylated porous Si microsensor displays a greater response to heptane than to IPA, whereas the other chemical modifications display a greater response to IPA than to heptane. The thermal oxide sensor displays a strong response to water vapor, while the acetylated material shows a relatively weak response. The results suggest that a combination of optical fiber sensors with different surface chemistries can be used to classify VOC analytes. Application of the miniature sensors to the detection of VOC breakthrough in a full-scale activated carbon respirator cartridge simulator is demonstrated. [Description provided by NIOSH]
• Subjects:
  Chemistry Chemistry, Analytic Occupational Health Safety
• Keywords:
  Analytical-chemistry Analytical-instruments Analytical-processes Author Keywords: Porous Silicon Chemical Sensors Organic-chemicals Organic-compounds Photonic Crystals Remote Sensors Samplers Sampling-equipment Volatile Organic Compounds Volatiles

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• ISSN:
  1616-301X
• Publisher:
  AFM
• Document Type:
  Text
• Genre:
  Journal Article
• Place as Subject:
  California ; OSHA Region 3 ; OSHA Region 9 ; Pennsylvania
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Division:
  NPPTL - National Personal Protective Technology Laboratory
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Volume:
  20
• Issue:
  17
• NIOSHTIC Number:
  nn:20037168
• Citation:
  Adv Funct Mater 2010 Sep; 20(17):2874-2883
• Contact Point Address:
  Michael J. Sailor, Department of Chemistry and Biochemistry, The University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0358 (USA)
• Email:
  msailor@ucsd.edu
• Federal Fiscal Year:
  2010
• Peer Reviewed:
  True
• Source Full Name:
  Advanced Functional Materials
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:349eb0b1de2e39d3bbb306fb29afe3d23616bceab958b9e444948863bba323419a0db884c05bc776f5138aa18d895e3240d0c14060853b74975349f617ff9290
• Download URL:
  https://stacks.cdc.gov/view/cdc/188302/cdc_188302_DS1.pdf
• File Type:
  [PDF - 604.91 KB ]