scholarly journals Colorimetric Detection of Hydrogen Sulfide in Ambient Air

Proceedings ◽  
2018 ◽  
Vol 2 (13) ◽  
pp. 804
Author(s):  
Laura Engel ◽  
Karina R. Tarantik ◽  
Carolin Pannek ◽  
Jürgen Wöllenstein
Keyword(s):  
Hydrogen Sulfide ◽  
Azo Dye ◽  
Screen Printing ◽  
Color Change ◽  
Colorimetric Detection ◽  
Ambient Air ◽  
Fast Method ◽  
Vis Spectroscopy

We present a fast method to monitor hydrogen sulfide (H2S) in ambient air based on a visible color change. Therefore, an immobilized copper(II) complex of the azo dye 1-(2-pyridylazo)-2-naphtol (H-PAN) was synthesized and prepared in a matrix for screen printing. Different materials, reaching from opaque paper to transparent foils served as substrate. The reaction of the copper(II) complex (Cu-PAN) to the target gas H2S was measured in reflection via UV/VIS spectroscopy.

scholarly journals Screen-Printed Sensors for Colorimetric Detection of Hydrogen Sulfide in Ambient Air

Sensors ◽  
2019 ◽  
Vol 19 (5) ◽  
pp. 1182 ◽  
Author(s):  
Laura Engel ◽  
Karina Tarantik ◽  
Carolin Pannek ◽  
Jürgen Wöllenstein
Keyword(s):  
Hydrogen Sulfide ◽  
Color Change ◽  
Colorimetric Detection ◽  
Preliminary Test ◽  
Ambient Air ◽  
Sensitive Material ◽  
Long Term Stability ◽  
Colorimetric Response ◽  
Vis Spectroscopy ◽  
Printed Sensors

A fast and sensitive method to monitor hydrogen sulfide (H2S) in ambient air based on a visible color change of a printed disposable sensor has been developed. As gas-sensitive material, an immobilized copper(II) complex of the azo dye 1-(2-pyridylazo)-2-naphtol (H-PAN) was synthesized and prepared in an ethyl cellulose matrix for screen printing. If H2S is present in ambient air, the gas sensitive layer changes its color from purple to yellow. A pre-primed polyethylene (PE) foil and a coated offset paper served as the printing substrate. The colorimetric response to the target gas was measured by UV/Vis spectroscopy in reflection at H2S concentrations between 1 to 20 ppm. Possible cross-sensitivities of the printed sensors towards methane (CH4), formaldehyde (CH2O), carbon monoxide (CO), ammonia (NH3), and nitrogen dioxide (NO2), as well as the long-term stability was investigated. Furthermore, reflection measurements of the Cu-PAN complex on an amorphous silica powder under gas admission served as preliminary test for the subsequent paste development.

Printed sensor labels for colorimetric detection of ammonia, formaldehyde and hydrogen sulfide from the ambient air

2021 ◽  
Vol 330 ◽  
pp. 129281
Author(s):  
Laura Engel ◽  
Ismael Benito-Altamirano ◽  
Karina R. Tarantik ◽  
Carolin Pannek ◽  
Martin Dold ◽  
...  
Keyword(s):  
Hydrogen Sulfide ◽  
Colorimetric Detection ◽  
Ambient Air

scholarly journals Essential properties and pitfalls of colorimetric Reverse Transcription Loop-mediated Isothermal Amplification as a point-of-care test for SARS-CoV-2 diagnosis

2021 ◽  
Vol 27 (1) ◽  
Author(s):  
Bruna de Oliveira Coelho ◽  
Heloisa Bruna Soligo Sanchuki ◽  
Dalila Luciola Zanette ◽  
Jeanine Marie Nardin ◽  
Hugo Manuel Paz Morales ◽  
...  
Keyword(s):  
Viral Load ◽  
Internal Control ◽  
Reverse Transcription ◽  
Color Change ◽  
Point Of Care ◽  
Colorimetric Detection ◽  
False Negative ◽  
Isothermal Amplification ◽  
Clinical Samples ◽  
Loop Mediated Isothermal Amplification

Abstract Background SARS-CoV-2 Reverse Transcription Loop-mediated Isothermal Amplification (RT-LAMP) colorimetric detection is a sensitive and specific point-of-care molecular biology technique used to detect the virus in only 30 min. In this manuscript we have described a few nuances of the technique still not properly described in the literature: the presence of three colors clusters; the correlation of the viral load with the color change; and the importance of using an internal control to avoid false-negative results. Methods To achieve these findings, we performed colorimetric RT-LAMP assays of 466 SARS-CoV-2 RT-qPCR validated clinical samples, with color quantification measured at 434 nm and 560 nm. Results First we determinate a sensitivity of 93.8% and specificity of 90.4%. In addition to the pink (negative) and yellow (positive) produced colors, we report for the first time the presence of an orange color cluster that may lead to wrong diagnosis. We also demonstrated using RT-qPCR and RT-LAMP that low viral loads are related to Ct values > 30, resulting in orange colors. We also demonstrated that the diagnosis of COVID-19 by colorimetric RT-LAMP is efficient until the fifth symptoms day when the viral load is still relatively high. Conclusion This study reports properties and indications for colorimetric RT-LAMP as point-of-care for SARS-CoV-2 diagnostic, reducing false results, interpretations and optimizing molecular diagnostics tests application.

Selective Colorimetric Detection of Hydrogen Sulfide Based on Primary Amine-Active Ester Cross-Linking of Gold Nanoparticles

2015 ◽  
Vol 87 (14) ◽  
pp. 7267-7273 ◽  
Author(s):  
Zhiqin Yuan ◽  
Fengniu Lu ◽  
Meihua Peng ◽  
Chia-Wei Wang ◽  
Yu-Ting Tseng ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Hydrogen Sulfide ◽  
Primary Amine ◽  
Colorimetric Detection ◽  
Cross Linking ◽  
Active Ester

scholarly journals Photocatalytical Degradation of Congo Red Azo Dye Using Phosphono-Aminoacid-Cd(II) Pendant Groups Grafted on a Polymeric Support

2019 ◽  
Vol 70 (10) ◽  
pp. 3473-3476 ◽  
Author(s):  
Laura Cocheci ◽  
Lavinia Lupa ◽  
Aniela Pop ◽  
Aurelia Visa ◽  
Bianca Maranescu ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Congo Red ◽  
Azo Dye ◽  
Organic Dyes ◽  
Degradation Process ◽  
Polymer Support ◽  
Polymeric Support ◽  
Vis Spectroscopy ◽  
Red Dye ◽  
Scanning Electron

In the present study, a new compound was used for decontaminating water polluted by Congo Red dye. Phosphono-aminoacid-Cd(II) pendant groups grafted on a polymeric support was prepared using impregnation of a polymer support functionalized with phosphono-aminoacid groups with an aqueous solution of Cd(NO3)2x4H2O. The catalyst was characterized by Fourier transform infrared ray, scanning electron microscope, termogravimetric analysis UV-Vis spectroscopy. The results suggest that the studied material could efficiently be used as photocatalyst in the degradation process of waters containing organic dyes under UV-Vis light irradiation.

scholarly journals Molecular Diagnostic of Ochratoxin A with Specific Aptamers in Corn and Groundnut via Fabrication of A Microfluidic Device

2021 ◽  
Author(s):  
Deepshikha Shahdeo ◽  
Azmat Ali Khan ◽  
Amer M Alanazi ◽  
Yun Suk Huh ◽  
Shruti Shukla ◽  
...  
Keyword(s):  
Ochratoxin A ◽  
Limit Of Detection ◽  
Colorimetric Assay ◽  
Animal Health ◽  
Colorimetric Detection ◽  
Molecular Diagnostic ◽  
Detection Range ◽  
Vis Spectroscopy ◽  
Wide Range ◽  
Analytical Device

Abstract Ochratoxin A (OTA) is one of the predominant mycotoxins that contaminate a wide range of food commodities. In the present study, a 36-mer aptamer was used as a molecular recognition element coupled with gold nanoparticles (AuNPs) for colorimetric detection of OTA in a microfluidic paper-based analytical device (µPADs). The µPADs consisted of three zones: control, detection, and sample, interconnected by channels. The biophysical characterizations of aptamer conjugated AuNPs were done by UV-vis spectroscopy (UV-vis), dynamic Light Scattering (DLS), and transmission electron microscopy (TEM). The developed colorimetric assay for OTA showed a limit of detection of 242, 545, and 95.69 ng/mL in water, corn, and groundnut, respectively. The HPLC detection method achieved acceptable coefficient in standard curves (r2 = 0.9995), better detection range, and recovery rates in spiked corn and groundnut samples as 43.61 ± 2.18% to 87.10 ± 1.82% and 42.01 ± 1.31% to 86.03 ± 2.64% after multiple sample extractions and cleanup steps. However, the developed µPADs analytical device had the potent ability to rapidly detect OTA without any extraction pre-requirement, derivatization, and cleanup steps, thus illustrating its feasibility in the animal health sector, agricultural, and food industries.

scholarly journals Direct Colorimetric Detection of Virus by a Polymerized Bilayer Assembly

1993 ◽  
Vol 330 ◽  
Author(s):  
Deborah H. Charych ◽  
Jon O. Nagy ◽  
Wayne Spevak ◽  
Joel Ager ◽  
Mark D. Bednarski
Keyword(s):  
Color Change ◽  
Colorimetric Detection ◽  
Self Assembled Monolayer ◽  
Visible Absorption ◽  
Polymer Backbone ◽  
Color Transition ◽  
Recognition Element ◽  
Ligand Interactions ◽  
Molecular Recognition Element ◽  
Bilayer Assembly

ABSTRACTScreening and detecting virus by receptor-ligand interactions presents an important challenge in medical and environmental diagnostics, and in drug development. We have developed a direct colorimetric detection method based on a polymeric bilayer assembly. The bilayer is composed of a self-assembled monolayer of octadecyl siloxane and a Langmuir-Blodgett layer of polydiacetylene. The polydiacetylene layer is functionalized with receptor-specific ligands such as analogs of sialic acid. The ligand serves as a molecular recognition element, while the conjugated polymer backbone signals binding at the surface by a chromatic transition. The color transition is readily visible to the naked eye as a blue to red color change and can be quantified by visible absorption spectroscopy. The color transition can be inhibited by the presence of soluble inhibitors. Raman spectroscopic analysis shows that the color transition may arise from binding induced strain on the material resulting in bond elongation and conjugation length reduction.

A fluorescent colorimetric azo dye based chemosensor for detection of S2− in perfect aqueous solution and its application in real sample analysis and building a molecular logic gate

2018 ◽  
Vol 10 (20) ◽  
pp. 2317-2326 ◽  
Author(s):  
Amit Kumar Manna ◽  
Jahangir Mondal ◽  
Rukmani Chandra ◽  
Kalyani Rout ◽  
Goutam Kumar Patra
Keyword(s):  
Aqueous Solution ◽  
Schiff Base ◽  
Azo Dye ◽  
Color Change ◽  
Logic Gate ◽  
Real Sample ◽  
Sample Analysis ◽  
Real Sample Analysis ◽  
Molecular Logic Gate ◽  
Molecular Logic

A fluorescent-colorimetric azo dye based bis-Schiff base chemosensor, L, has been developed. L can selectively detect S2− through a color change from yellow to orange in perfect aqueous solution by deprotonation mechanism.

Measurements and Comparative Air Quality Analysis of a Goat Farm Operation

2019 ◽  
Vol 62 (6) ◽  
pp. 1723-1733
Author(s):  
Arndreya Howard ◽  
Venkata S. V. Botlaguduru ◽  
Hongbo Du ◽  
Raghava R. Kommalapati ◽  
Ziaul Huque
Keyword(s):  
Hydrogen Sulfide ◽  
Air Quality ◽  
Solar Radiation ◽  
Multiple Regression ◽  
Air Pollutants ◽  
Emission Rate ◽  
Particle Diameter ◽  
Ambient Air ◽  
Meteorological Conditions ◽  
Goat Farm

Abstract. Air pollutants such as hydrogen sulfide, ammonia, particulate matter (PM10 and PM2.5), methane, and volatile organic compounds (VOCs) are harmful to the respiratory systems of humans and animals. Livestock facilities have been documented as a major source of dangerous air pollutants; however, there is a lack of data on the emissions from goat farms. This study investigated a goat farm in Texas to evaluate the emission levels and determine the correlation of meteorological conditions with these pollutants. Two locations on the goat farm were selected for monitoring: inside a goat barn, and at a manure lagoon. The monitoring campaign was conducted over a 53-day period during winter and summer seasons. Carbon dioxide, ozone, nitrous oxide, ammonia, PM10, PM2.5, hydrogen sulfide, methane, and VOCs were measured to determine hourly average concentrations using chemiluminescent instruments. An analysis of meteorological conditions using multiple regression was conducted to investigate probable correlations between emission rates and characteristic climate data, such as temperature, humidity, barometric pressure, and solar radiation. Particle size distributions of PM10 and PM2.5 were evaluated for the two monitoring locations during the different seasons to determine the typical particle diameter and the impact of season on particle diameter. The highest emission rate of 364.4 ±50 g m-2 d-1 occurred at the manure lagoon for methane, which contributed the most to the overall emissions at this animal operation. The regression results for the manure lagoon had the highest positive correlations for ozone with temperature and solar radiation. The outdoor meteorological conditions had the most significant influence on pollutants at both locations. Therefore, meteorological conditions are instrumental in the intensity of the air pollutants found on animal farms. The particle diameters ranged from 0.1 to 6.0 µm in the goat barn and from 0.3 to 1.0 µm at the manure lagoon. Even though moderate levels of emissions were monitored at this facility, the emissions from the goat farm do not pose a risk to human health and do not significantly impact the ambient air quality when compared to other livestock facilities.HighlightsEmissions from a goat farm were measured inside a goat barn and at a manure lagoon over summer and winter seasons.The highest methane emission rate of 364.4 ±50 g m-2 d-1 occurred at the manure lagoon during summer.Meteorological conditions significantly influenced emissions at both locations, especially for O3 at the manure lagoon.Emissions from goat farm operations are much lower than those from cow, swine, and chicken farm operations. Keywords: Air quality, Ammonia, Emissions, Goat farm, Methane, Multiple regression analysis.

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