Optical Techniques for Detecting and Identifying Biological-Warfare Agents

Greenwood, Darryl P.; Jeys, T. H.; Johnson, Bernadette; Richardson, Jonathan M.; Shatz, Michael P.

doi:10.1109/jproc.2009.2013564

Cited by 25 publications

(8 citation statements)

References 73 publications

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“…Also, although near-UV (300 to 400 nm) LEDs are currently used for biological detection because they are much more efficient and generate more output power than MUV LEDs, shorter wavelengths will be more efficient in detecting biological particles due to the increase in fluorescence cross section. 1) The results presented in this letter are approaching the output power and efficiency needed to begin replacing current mid-ultraviolet sources in specialized applications.…”

mentioning

confidence: 84%

High Output Power from 260 nm Pseudomorphic Ultraviolet Light-Emitting Diodes with Improved Thermal Performance

Grandusky¹,

Gibb²,

Mendrick³

et al. 2011

Appl. Phys. Express

146

107

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This letter reports on the improved performance of a pseudomorphic ultraviolet light-emitting diode (LED). At 100 mA input current, 9.2 mW of quasi-CW output power was measured in a calibrated integrating sphere. The addition of a heat sink, required for CW and higher power operation, introduced a numerical aperture of 0.86, and 72 mW was measured in pulsed mode at 1.7 A, indicating that the total output power exceeds 100 mW when corrected by the coupling factor. The high characteristic temperature of 983 K was instrumental in achieving these record output powers for an LED with wavelength shorter than 265 nm. #

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mentioning

confidence: 84%

High Output Power from 260 nm Pseudomorphic Ultraviolet Light-Emitting Diodes with Improved Thermal Performance

Grandusky¹,

Gibb²,

Mendrick³

et al. 2011

Appl. Phys. Express

146

107

View full text Add to dashboard Cite

show abstract

“…An aerosol attack would work optimally as a fine mist of 1-5 μm-sized particles, since particles in this size range find optimum inhalation and retention 15 the same size range, considered as a range for wavelengths, belongs to infrared (IR) spectrum. This implies the relevance of LIDARS for direct detection 16 . On the other hand, when ultraviolet (UV) radiation is used as illumination source, the radiation may induce fluorescence from aerosolized material within the light beam path.…”

Section: Biological and Chemical Warfare Agentsmentioning

confidence: 96%

Photonics for Detection of Chemicals, Drugs and Explosives

Garibbo¹,

Palucci²

2013

Photonics for Safety and Security

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Detection of chemicals, drugs and explosives is a relevant task for countering terrorism and organized crime by preventing their effects on airports, land borders, seaports, through the whole supply chain or in mass transit, as in metro or railway stations.Photonics and spectroscopic techniques are commonly used to retrieve information on atomic and molecular energy levels, molecular geometries, chemical bonds, interactions of molecules, and related processes. For their capacity to investigate at structure of the matter level these technologies are deemed an excellent instrument for safety and security protection, inspection and investigation.Even if threat is changing continuously and photonic systems may not work properly in certain circumstances, it makes sense to continue to invest in photonics, since photonics remains one of the best means to investigate molecular structures of compounds; for this reason, photonic sensors are nowadays considered as the first detection technology for hazardous materials as explosive compounds.

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“…In response to these shortcomings, a new generation of online, automated instruments for the measurement of PBAP, such as aerosol mass spectrometers (Tobias et al, 2005) and fluorescent particle spectrometers (Pan et al, 2003;Kaye et al, 2005), have recently been developed. Measurements of single-particle fluorescence has been used for rapid detection of PBAP in the fields of atmospheric science (Pöschl et al, 2010), public health (Bhangar et al, 2015), and biological warfare research (Greenwood et al, 2009). Many biological compounds, including certain amino acids (e.g., tryptophan, tyrosine), metabolic small molecules (e.g., the reduced form of nicotinamide adenine dinucleotide, or NADH), and some proteins (e.g., green fluorescent protein), are intrinsically fluorescent (Chudakov et al, 2010).…”

Section: Introductionmentioning

confidence: 99%

Fluorescence calibration method for single-particle aerosol fluorescence instruments

et al. 2017

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Abstract. Real-time, single-particle fluorescence instruments used to detect atmospheric bioaerosol particles are increasingly common, yet no standard fluorescence calibration method exists for this technique. This gap limits the utility of these instruments as quantitative tools and complicates comparisons between different measurement campaigns. To address this need, we have developed a method to produce size-selected particles with a known mass of fluorophore, which we use to calibrate the fluorescence detection of a Wideband Integrated Bioaerosol Sensor (WIBS-4A). We use mixed tryptophan-ammonium sulfate particles to calibrate one detector (FL1; excitation = 280 nm, emission = 310-400 nm) and pure quinine particles to calibrate the other (FL2; excitation = 280 nm, emission = 420-650 nm). The relationship between fluorescence and mass for the mixed tryptophan-ammonium sulfate particles is linear, while that for the pure quinine particles is nonlinear, likely indicating that not all of the quinine mass contributes to the observed fluorescence. Nonetheless, both materials produce a repeatable response between observed fluorescence and particle mass. This procedure allows users to set the detector gains to achieve a known absolute response, calculate the limits of detection for a given instrument, improve the repeatability of the instrumental setup, and facilitate intercomparisons between different instruments. We recommend calibration of single-particle fluorescence instruments using these methods.

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Optical Techniques for Detecting and Identifying Biological-Warfare Agents

Cited by 25 publications

References 73 publications

High Output Power from 260 nm Pseudomorphic Ultraviolet Light-Emitting Diodes with Improved Thermal Performance

High Output Power from 260 nm Pseudomorphic Ultraviolet Light-Emitting Diodes with Improved Thermal Performance

Photonics for Detection of Chemicals, Drugs and Explosives

Fluorescence calibration method for single-particle aerosol fluorescence instruments

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