Development and comparison of pH microoptodes for use in marine systems

Oliver Kohls, Ingo Klimant, Gerhard Holst, Michael Kühl

Research output: Contribution to journalConference articleResearchpeer-review

9 Citations (Scopus)

Abstract

Traditionally microscale measurements of pH are based on potentiometric measurements with a pH glass microelectrode. The preparation of these electrodes is, however, very time consuming. We developed pH micro-optodes for use in seawater in the range of pH 7 - 9. The optodes are based on immobilized acid-base indicators, which change their color and/or fluorescence properties as a function of the pH. Various dyes were immobilized directly on the tip of a tapered optical fiber by different techniques. We then investigated these pH optodes with respect to response time, mechanical stability and calibration characteristics. Dependent on the optical properties of the indicator material we used different light emitting diodes (LED's) as the light sources and either a photodiode or a photomultiplier as detector.

Original languageEnglish
JournalProceedings of SPIE - The International Society for Optical Engineering
Volume2978
Pages (from-to)82-91
Number of pages10
ISSN0277-786X
DOIs
Publication statusPublished - 1997
Externally publishedYes
EventMicro- and Nanofabricated Electro-Optical Mechanical Systems for Biomedical and Environmental Applications - San Jose, CA, United States
Duration: 10 Feb 199710 Feb 1997

Conference

ConferenceMicro- and Nanofabricated Electro-Optical Mechanical Systems for Biomedical and Environmental Applications
Country/TerritoryUnited States
CitySan Jose, CA
Period10/02/199710/02/1997

Keywords

  • Environmental sensing
  • Fiber-optic
  • Optical microsensor
  • Optode
  • pH
  • Seawater

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