Mid-ultraviolet light-emitting diode detects dipicolinic acid.
- Texas Tech University, Lubbock, TX
Dipicolinic acid (DPA, 2,6-pyridinedicarboxylic acid) is a substance uniquely present in bacterial spores such as that from anthrax (B. anthracis). It is known that DPA can be detected by the long-lived fluorescence of its terbium chelate; the best limit of detection (LOD) reported thus far using a large benchtop gated fluorescence instrument using a pulsed Xe lamp is 2 nM. We use a novel AlGaN light-emitting diode (LED) fabricated on a sapphire substrate that has peak emission at 291 nm. Although the overlap of the emission band of this LED with the absorption band of Tb-DPA ({lambda}{sub max} doublet: 273, 279 nm) is not ideal, we demonstrate that a compact detector based on this LED and an off-the-shelf gated photodetection module can provide an LOD of 0.4 nM, thus providing a basis for convenient early warning detectors.
- Research Organization:
- Sandia National Laboratories
- Sponsoring Organization:
- USDOE
- DOE Contract Number:
- AC04-94AL85000
- OSTI ID:
- 973671
- Report Number(s):
- SAND2005-4039J
- Journal Information:
- Proposed for publication in Applied Spectroscopy., Journal Name: Proposed for publication in Applied Spectroscopy. Journal Issue: 11 Vol. 58; ISSN 0003-7028; ISSN APSPA4
- Country of Publication:
- United States
- Language:
- English
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