Quantum cascade laser-based photoacoustic spectroscopy for trace vapor detection and molecular discrimination

Sensors (Basel). 2010;10(3):1986-2002. doi: 10.3390/s100301986. Epub 2010 Mar 11.

Abstract

We report on the development of a microelectromechanical systems (MEMS)-scale photoacoustic sensor for the detection of trace gases. A mid-infrared quantum cascade laser (QCL) was used to determine detection limits for acetic acid, acetone, 1,4-dioxane, and vinyl acetate. The source was continuously tunable from 1015 cm(-1) to 1240 cm(-1), allowing for the collection of photoacoustic vibrational spectra for these gases. Exceptional agreement between the measured photoacoustic spectra and the infrared spectra for acetic acid, acetone, 1,4-dioxane, and vinyl acetate was observed. Partial least-squares (PLS) regression was used to develop an algorithm for classification of these compounds based solely on photoacoustic spectra.

Keywords: MEMS; chemometrics; photoacoustic spectroscopy; quantum cascade laser; sensor.

MeSH terms

  • Acetic Acid / chemistry
  • Acetone / chemistry
  • Algorithms
  • Dioxanes / chemistry
  • Gases / analysis*
  • Gases / classification
  • Lasers, Semiconductor*
  • Least-Squares Analysis
  • Limit of Detection
  • Micro-Electrical-Mechanical Systems
  • Photoacoustic Techniques* / instrumentation
  • Photoacoustic Techniques* / methods
  • Spectrum Analysis / methods*
  • Vinyl Compounds / chemistry

Substances

  • Dioxanes
  • Gases
  • Vinyl Compounds
  • Acetone
  • 1,4-dioxane
  • vinyl acetate
  • Acetic Acid