Detection of nerve agent stimulants based on photoluminescent porous silicon interferometer

Abstract

Porous silicon (PSi) exhibiting dual optical properties, both Fabry-Pérot fringe and photolumincence, was developed and used as chemical sensors. PSi samples were prepared by an electrochemical etch of p-type silicon under the illumination of 300-W tungsten lamp during the etch process. The surface of PSi was characterized by cold field-emission scanning electron microscope. PSi samples exhibited a strong visible orange photoluminescence at 610 nm with an excitation wavelength of 460 nm as well as Fabry-Pérot fringe with a tungsten light source. Both reflectivity and photoluminescence were simultaneously measured under the exposure of organophosphate vapors. An increase of optical thickness and quenching photoluminescences under the exposure of various organophosphate vapors were observed.

Boron nitride nanoclusters as a sensor for Cyclosarin nerve agent: DFT and thermodynamics studies

“…Cyclosarin (GF) is a highly toxic organophosphate that belongs to the member of nerve used in the Gulf War (GW) operations [3,4]. Various methods introduced for nerve agent detection including chromatography [5], mass spectroscopy [6], photoluminescent [7] and fluorescent sensors [8]. By the advent of nanotechnology, nanostructures have attracted an extensive attention as gas sensors because their surface/volume ratio is much higher than that of the conventional micro sensors which makes the large adsorption area available for adsorption process [9][10][11][12][13][14][15][16][17][18].…”

Vapor Selectivity of a Natural Photonic Crystal to Binary and Tertiary Mixtures Containing Chemical Warfare Agent Simulants

“…The use of both natural and synthetic PhCs as vapor sensors has been widely explored over the last twenty years [5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23], though relatively few studies have examined their viability as CWA simulant detectors [24][25][26][27][28][29][30][31][32]. Typically, these studies have involved synthetic PhCs composed of porous silicon.…”

“…Porous silicon PhCs without selective features (e.g., no functionalization) have detected the presence of CWA simulants via shifts in reflectance spectra with sensitivity as low as 4 ppm [27], though signatures were not unique and were a function of refractive index and concentration of the analyte vapor [27,28]. To introduce a degree of selectivity towards CWA simulants, porous silicon sensors have been fabricated with coatings containing functional groups reactive to CWAs and CWA simulants [25,26,29,30,32]. Generally, interaction of the CWA or CWA simulant with the coating caused a change in the thickness of the coating and thus the periodic spacing of the PhC, resulting in a detectable response that was restricted to analytes that react with the coating.…”

Detection of Organic Vapors Based on Photoluminescent Bragg-Reflective Porous Silicon Interferometer

“…9 Typically, PS exhibiting a well-defined reflection peak in the optical reflectivity spectrum can be prepared with p-type silicon wafer under the dark condition. Detection of molecules such as toxic gases, [10][11][12] organic solvents, 13 DNA, 3 and proteins 14 15 can lead to a shift of reflection peak due to a change in the refractive index of PS. Luminescent PS samples are usually prepared by a galvanostatic photoetch of n-type silicon wafer under the illumination condition.…”