J. Phys. IV France
Volume 125, June 2005
Page(s) 773 - 775

J. Phys. IV France 125 (2005) 773-775

DOI: 10.1051/jp4:2005125178

Isotope-selective sensor for medical diagnostics based on PAS

M. Wolff1, 2, H.G. Groninga1 and H. Harde2

1  PAS-Tech GmbH, Bahnhofstrasse 3, 19246 Zarrentin, Germany
2  Helmut-Schmidt-University, Holstenhofweg 85, 22043 Hamburg, Germany

Development of new optical sensor technologies has a major impact on the progression of diagnostic methods. Of the permanently increasing number of non-invasive 13C-breath tests, the Urea Breath Test for detection of Helicobacter pylori is the most prominent. However, many recent developments go beyond gastroenterological applications. We present a new detection scheme for breath analysis that employs an especially compact and simple set-up based on Photoacoustic Spectroscopy. Using a wavelength-modulated DFB-diode laser and taking advantage of acoustical resonances of the sample cell, we performed very sensitive isotope-selective measurements on CO2. Detection limits for 13CO2 of a few ppm and for the variation of the 13CO2 concentration of approximately 1% were achieved.

© EDP Sciences 2005