Dye-doped organically modified silica glass for fluorescence based carbon dioxide gas detection

Malins, Chris; MacCraith, Brian D.

doi:10.1039/a805803b

Cited by 62 publications

(42 citation statements)

References 31 publications

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“…The response and recovery times are lower than those obtained for other systems developed by us [29;30;47], especially the recovery time, which was half of that obtained before. The response and recovery times obtained here are comparable and even lower than other sensing schemes widely used for CO2 sensing [48][49][50]. The precision of proposed prototype was measured by studying the intra-day reproducibility.…”

Section: Analytical Characterizationmentioning

confidence: 74%

A new light emitting diode–light emitting diode portable carbon dioxide gas sensor based on an interchangeable membrane system for industrial applications

Vargas-Sansalvador

Fay

Phelan

et al. 2011

Analytica Chimica Acta

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A new system for CO2 measurement (0-100%) by based on a paired emitter-detector diode arrangement as a colorimetric detection system is described. Two different configurations were tested: configuration 1 (an opposite side configuration) where a secondary inner-filter effect accounts for CO2 sensitivity. This configuration involves the absorption of the phosphorescence emitted from a CO2-insensitive luminophore by an acid-base indicator and configuration 2 wherein the membrane containing the luminophore is removed, simplifying the sensing membrane that now only contains the acid-base indicator. In addition, two different instrumental configurations have been studied, using a paired emitter-detector diode system, consisting of two LEDs wherein one is used as the light source (emitter) and the other is used in reverse bias mode as the light detector. The first configuration uses a green LED as emitter and a red LED as detector, whereas in the second case two identical red LEDs are used as emitter and detector. The system was characterised in terms of sensitivity, dynamic response, reproducibility, stability and temperature influence. We found that configuration 2 presented a better CO2 response in terms of sensitivity.Key words. Carbon dioxide sensor; Gas sensor; Optical sensor; Paired emitter detector-diode sensor; Portable instrumentation. INTRODUCTIONCO2 is an important industrial gas for many different uses that include production of chemicals (e.g. urea ), inert agent for food packaging (to extend the shelf-life of meat, cheese, etc.), beverages, refrigeration systems, welding systems, fire extinguishers, water treatment processes, and many other smaller scale applications [1;2]. In the agro-food industry CO2 is widely used in modified-atmosphere packaging where its task is to inhibit growth of spoilage bacteria [3;4]. For instance, in active packaging technologies a CO2 generating system can be considered as a technique complimentary to oxygen scavenging [5]. High CO2 levels (10-80 %) are desirable for foods such as meat and poultry in order to inhibit surface microbial growth and to extend their life time. The maintenance of CO2 concentration within packages in food [6], as instance using inserted sachets [7;8], must be carefully monitored since CO2 permeability is 3-5 times higher than that of oxygen for most of the plastic films and because CO2 is absorbed by many foods like meat and poultry. Real-time process monitoring is fundamental for effective process control. The rapid development of bioprocess applications together with the agro-food industry have led to an intensive search for new sensors capable of providing real-time information about the state of the processes. Conventional methods for CO2 determination include, among others, infrared spectrometry [9] or electrochemical sensors based on liquid (Severinghaus-type electrodes) or solid electrolytes [10;11]. The most popular sensors used for CO2 gas sensing in biotechnological applications are based on electrochemical measurements that can...

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Section: Analytical Characterizationmentioning

confidence: 74%

A new light emitting diode–light emitting diode portable carbon dioxide gas sensor based on an interchangeable membrane system for industrial applications

Vargas-Sansalvador

Fay

Phelan

et al. 2011

Analytica Chimica Acta

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“…[37][38][39][40][41]. One of the earliest studies reported in Table 2, used agarose as the encapsulation medium [32], but required a gas-permeable membrane to stop the film drying out and also to allow its use for making dissolved CO 2 measurements.…”

Section: Page 4 Of 25 Analystmentioning

confidence: 99%

Highly CO₂sensitive extruded fluorescent plastic indicator film based on HPTS

Mills

Yusufu

2016

Analyst

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Highly-sensitive optical fluorescent extruded plastic films are reported for the detection of gaseous and dissolved CO 2 . The pH-sensitive fluorescent dye used is 8-Hydroxypyrene-1,3,6-trisulfonic acid trisodium salt (HPTS, PTS -) coated on the surface of hydrophilic fumed silica and the base is tetrabutylammonium hydroxide (TBAH). The above components are used to create an HPTS pigment (i.e. HPTS/SiO 2 /TBAH) with a high CO 2 sensitivity (%CO 2 (S=1/2) = 0.16%) and fast 50% response (t 50↓ ) = 2 s and recovery (t 50↑ ) = 5 s times. Highly CO 2 -sensitive plastic films are then fabricated, via the extrusion of the HPTS pigment powder in low-density polyethylene (LDPE). As with the HPTS-pigment, the luminescence intensity (at 515 nm) and absorbance (at 475 nm) of the HPTS plastic film decreases as the %CO 2 in the ambient gas phase increases. The HPTS plastic film exhibits a high CO 2 sensitivity, %CO 2 (S=1/2), of 0.29%, but a response time ˂ 2 min and recovery time ˂ 40 min, which is slower than that of the HPTS pigment. The HPTS plastic film is very stable under ambient conditions, (with a shelf life ˃ six month when stored in the dark but under otherwise ambient conditions). Moreover, the HPTS-LDPE film is stable in water, salt solution and even in acid (pH=2), and in each of these media it can be used to detect dissolved CO 2 .

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“…(9). Table 3 provides details of many of the dry luminescent optical films for carbon dioxide that have been reported in the literature [51][52][53][54][55][56][57][58][59][60][61][62][63][64][65][66][67][68][69][70] and, as with the wet indicators, reviewed earlier, see table 1, most are intensity-rather than lifetime-, based sensors. Almost all these sensors utilise the ion-pair technology developed by Mills et al 44,45 .…”

Section: Dry Optical Sensors For Carbon Dioxidementioning

confidence: 99%

“…Continuing the theme of novel encapsulating media, a dry optical sensor for carbon dioxide, employing the HPTS-tetraoctyl ammonium cation ion pair has been developed 56 which uses an organically modified silica glass (ormosil), rather than an organic polymer, as an encapsulation medium. In this study a relatively high humidity was maintained in all test and sample gases, since work showed the dry luminescent sensor film to be quite sensitive towards variations in humidity.…”

Section: Dry Optical Sensors For Carbon Dioxidementioning

confidence: 99%

Fluorescent Carbon Dioxide Indicators

Mills

Hodgen

Topics in Fluorescence Spectroscopy

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Dye-doped organically modified silica glass for fluorescence based carbon dioxide gas detection

Cited by 62 publications

References 31 publications

A new light emitting diode–light emitting diode portable carbon dioxide gas sensor based on an interchangeable membrane system for industrial applications

A new light emitting diode–light emitting diode portable carbon dioxide gas sensor based on an interchangeable membrane system for industrial applications

Highly CO₂sensitive extruded fluorescent plastic indicator film based on HPTS

Fluorescent Carbon Dioxide Indicators

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Dye-doped organically modified silica glass for fluorescence based carbon dioxide gas detection

Cited by 62 publications

References 31 publications

A new light emitting diode–light emitting diode portable carbon dioxide gas sensor based on an interchangeable membrane system for industrial applications

A new light emitting diode–light emitting diode portable carbon dioxide gas sensor based on an interchangeable membrane system for industrial applications

Highly CO2sensitive extruded fluorescent plastic indicator film based on HPTS

Fluorescent Carbon Dioxide Indicators

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Product

Resources

About

Highly CO₂sensitive extruded fluorescent plastic indicator film based on HPTS