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NIR optical carbon dioxide gas sensor based on simple azaBODIPY pH indicators
NIR optical carbon dioxide gas sensor based on simple azaBODIPY pH indicators
- Source :
- The Analyst. 144:3870-3877
- Publication Year :
- 2019
- Publisher :
- Royal Society of Chemistry (RSC), 2019.
-
Abstract
- Two simple boron-dipyrromethene-type fluorophore (azaBODIPYs) dyes are synthesized and tested for the determination of CO2 gas by an inner filter process. The indicators are noncovalently entrapped in suitable polymers according to their polarity, featuring absorption maxima at 620 nm and fluorescent emission maxima in the range 675–720 nm. Molar absorptivity and fluorescence quantum yield data were determined for these two synthesized azaBODIPYs. These indicators have high molar absorption coefficients of 7.1 × 104 and 2.1 × 104 M−1 cm−1 and quantum yields of 21 and 9%. The pKa values of the indicators are determined from absorbance and fluorescence measurements with values of 7.9 and 8.5, depending on the positioning of the substitution pattern of the electron-donating functionalities. The two azaBODIPYs present excellent photostability, making them suitable for long duration measurements. These azaBODIPY dyes act as fluorescent pH indicators in a polymeric sensing membrane along with microcrystalline powder of chromium-doped gadolinium aluminium borate as the luminophore, a transfer phase agent (tetraoctyl or tetramethyl ammonium hydroxide) and a plasticizer or surfactant to improve membrane permeability to gaseous CO2. The response time ranges from 42 to 60 s and recovery time from 103 to 120 s, with a detection limit of 0.04 and 0.57% CO2. The store time of the sensing membranes is longer than 570 days in the best case, and it does not need to be kept in any special atmosphere other than darkness.
- Subjects :
- Fluorophore
Materials science
Membrane permeability
010401 analytical chemistry
Analytical chemistry
Quantum yield
02 engineering and technology
Molar absorptivity
021001 nanoscience & nanotechnology
01 natural sciences
Biochemistry
Fluorescence
0104 chemical sciences
Analytical Chemistry
Absorbance
chemistry.chemical_compound
chemistry
Electrochemistry
Luminophore
Environmental Chemistry
Absorption (chemistry)
0210 nano-technology
Spectroscopy
Subjects
Details
- ISSN :
- 13645528 and 00032654
- Volume :
- 144
- Database :
- OpenAIRE
- Journal :
- The Analyst
- Accession number :
- edsair.doi.dedup.....9f62f7d8e384d8573e92314fd0696180
- Full Text :
- https://doi.org/10.1039/c9an00432g