Optical Ammonia Sensor for Continuous Bioprocess Monitoring

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We present an optical ammonia sensor suitable for bioprocess monitoring. A fluorescent dye is physically entrapped in a polyurethane hydrogel forming an emulsion system with vinylterminated polydimethylsiloxane (PDMS). The sensing layer is covered by a hydrophobic porous membrane which excludes hydrophilic substances. Ammonia, diffuses through this barrier and PDMS to the protonated dye, whereby it deprotonates the dye and switches off its emission. Readout is performed with a miniaturized phase fluorimeter combined with optical fibers. Dual-lifetime referencing (DLR) acts as detection method and Egyptian blue as reference material.
Original languageEnglish
Title of host publicationProceedings Eurosensors 2018
EditorsAnton Köck, Marco Deluca
PublisherMDPI AG
Number of pages4
Publication statusPublished - 19 Nov 2018
EventEurosensors 2018 - Karl Franzens Universität Graz, Graz, Austria
Duration: 9 Sep 201812 Sep 2018


ConferenceEurosensors 2018
Internet address



  • Ammonia
  • optical sensor
  • process monitoring
  • fluorescent dye

Cite this

Maierhofer, M., Borisov, S., & Mayr, T. (2018). Optical Ammonia Sensor for Continuous Bioprocess Monitoring. In A. Köck, & M. Deluca (Eds.), Proceedings Eurosensors 2018 (Vol. 2). [1041] MDPI AG.