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Detection of nitrite by flow injection analysis using a novel paired emitter-detector diode (PEDD) as a photometric detector

O'Toole, Martina and Shepherd, Roderick and Lau, King-Tong and Diamond, Dermot (2007) Detection of nitrite by flow injection analysis using a novel paired emitter-detector diode (PEDD) as a photometric detector. In: Advanced Environmental, Chemical, and Biological Sensing Technologies V , 10 September 2007, Boston, MA, USA .

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An inexpensive flow injection analysis system for determining low concentration levels of nitrite employing the Griess reagent spectrophotometric method is reported. The novel photometric detector applied within this manifold is a highly sensitive, low cost, miniaturized light emitting diode (LED) based flow detector. This colorimetric detector employs two LEDs, operating one as a light source and the other as a light detector. The emitter LED is forward biased and the detector reverse biased. The emitter and detector LED had a λmax of 530 nm and 623 nm respectively. The emission spectrum of the emitter LED efficiently overlapped with the absorbance spectrum of 9 µM NO2 and Griess reagent complex. A simple timer circuit measures the time taken for the photocurrent generated by the emitter LED to discharge the detector LED from 5 V (logic 1) to 1.7 V (logic 0). The Griess reagent method employed for nitrite determination is based on the formation of an azo dye, the intensity of which is directly related to nitrite concentration. The linear range, reproducibility and limit of detection were investigated. Detection limits in the nanomolar range were achieved using the Paired Emitter-Detector Diode (PEDD) flow analysis device. For a comparative study the linear range and limit of detection were also investigated using a platewell reader. Higher sensitivity and improved precision were obtained from the PEDD compared to the commercially available plate well reader.

Item Type:Conference or Workshop Item (Paper)
Event Type:Conference
Uncontrolled Keywords:Light emitting diodes; Optical sensing; Nitrite Detection; Griess Reaction and Flow Analysis;
Subjects:Physical Sciences > Analytical chemistry
Physical Sciences > Environmental chemistry
Physical Sciences > Detectors
Physical Sciences > Chemistry
DCU Faculties and Centres:DCU Faculties and Schools > Faculty of Science and Health > School of Chemical Sciences
Research Initiatives and Centres > Adaptive Information Cluster (AIC)
Research Initiatives and Centres > National Centre for Sensor Research (NCSR)
Published in:Proceedings of SPIE. 6755, 67550P. SPIE - The International Society for Optical Engineering.
Publisher:SPIE - The International Society for Optical Engineering
Official URL:
Copyright Information:©2007 COPYRIGHT SPIE--The International Society for Optical Engineering. One print or electronic copy may be made for personal use only. Systematic electronic or print reproduction and distribution, duplication of any material in this paper for a fee or for commercial purposes, or modification of the content of the paper are prohibited.
Funders:Science Foundation Ireland
ID Code:2979
Deposited On:16 Mar 2009 16:53 by martina o'toole. Last Modified 31 Mar 2009 11:42

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