University of Hertfordshire

A low-cost multi-channel aerosol fluorescence sensor for networked deployment.

Research output: Chapter in Book/Report/Conference proceedingConference contribution

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  • 901849

    Accepted author manuscript, 720 KB, PDF document

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Original languageEnglish
Title of host publicationProcs SPIE European Symposium Optics/Photonics in Security & Defence
Subtitle of host publicationOptically Based Biological and Chemical Sensing for Defence
EditorsJohn Carrano, Arturas Zukauskas
Place of PublicationUSA
Pages388-398
Volume5617
DOIs
Publication statusPublished - 2004

Abstract

We describe a low-cost prototype bio-aerosol fluorescence sensor designed for unattended deployment in medium to large area networks. The sensor uses two compact xenon flash units to excite fluorescence in an aerosol sample volume drawn continuously from the ambient environment. In operation, the xenons are pulsed alternately at 300ms intervals whilst absorption filters restrict their radiation output to UV bands ~260-290nm and ~340-380nm respectively, optimal for exciting the biological fluorophores tryptophan and NADH. Fluorescence from all particles instantaneously present within a sensing volume is measured using two miniature photomultiplier detectors optically filtered to detect radiation in the bands ~320-600nm and ~410-600nm. The second of these bands covers the principal emission from NADH, whilst the difference between the first and second detector channels yields fluorescence in the 320-410nm band, covering much of the tryptophan emission. Whilst each sensor is clearly limited in specificity, the low sensor cost (<$5k) offers potential for the deployment in large networks that would be prohibitively expensive using particle fluorescence sensors based on currently available UV lasers. Preliminary details are also given of a variant of the sensor, currently under development, in which xenon illumination is used to acquire single particle fluorescence data at rates of up to 200 particles per second.

ID: 487582