Characterization of a modular microfluidic photoionization detector

Rezende, Gustavo Coelho; Calvé, Stéphane Le; Brandner, Juergen J.; Newport, David

doi:10.1016/j.snb.2020.128667

Cited by 12 publications

(4 citation statements)

References 14 publications

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“…Gas analyzers and sensors are required in a large number of industrial and scientific applications for the analysis of matter [1][2][3]. Such analyzers have wide application prospects as detectors in gas chromatography [4], in gas medium control * Authors to whom any correspondence should be addressed.…”

Section: Introductionmentioning

confidence: 99%

Use of plasma electron spectroscopy method to detect hydrocarbons, alcohols, and ammonia in nonlocal plasma of short glow discharge

Chen

Yao

Saifutdinov

et al. 2021

Plasma Sources Sci. Technol.

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The method of plasma electron spectroscopy (PLES) is further developed for the analysis of impurities of organic molecules and ammonia in this work. In particular, for the first time the PLES method was used to detect the hydrocarbons impurities: alkanes (methane) and alkenes (ethylene), as well as their derivatives alcohols (ethanol), radicals, and ammonia. As the energies of the registered characteristic electrons are different for different chemical compounds, an important advantage of the PLES method is the fact that it allows simultaneous (in one measurement) registration of various impurities. This work presents a prototype of a PLES-gas analyzer based on nonlocal plasma of negative glow of a short glow discharge in helium.

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Section: Introductionmentioning

confidence: 99%

Use of plasma electron spectroscopy method to detect hydrocarbons, alcohols, and ammonia in nonlocal plasma of short glow discharge

Chen

Yao

Saifutdinov

et al. 2021

Plasma Sources Sci. Technol.

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“…Therefore, real-time monitoring of multiple VOCs and early warnings of air pollution have extreme significance in air quality assessment and human health protection [ 8 ]. At present, the identification and quantification of atmospheric VOCs mainly rely on analytical instruments such as gas chromatography (GC) and mass spectrometry (MS), which are commonly used for the accurate analysis of air components [ 9 , 10 , 11 , 12 , 13 ]. However, despite high accuracy and low detection limits, those spectroscopic methods usually require expensive instruments, complex sample handling, and long analysis periods, which are not conducive to frequent air quality assessments in daily life [ 14 , 15 , 16 ].…”

Section: Introductionmentioning

confidence: 99%

Facile Synthesis of ZnO/WO3 Nanocomposite Porous Films for High-Performance Gas Sensing of Multiple VOCs

et al. 2023

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Volatile organic compounds (VOCs) in indoor environments have typical features of multiple components, high concentration, and long duration. The development of gas sensors with high sensitivity to multiple VOCs is of great significance to protect human health. Herein, we proposed a sensitive ZnO/WO3 composite chemi-resistive sensor facilely fabricated via a sacrificial template approach. Based on the transferable properties of self-assembled monolayer colloidal crystal (MCC) templates, two-dimensional honeycomb-like ordered porous ZnO/WO3 sensing matrixes were constructed in situ on commercial ceramic tube substrates with curved and rough surfaces. The nanocomposite thin films are about 250 nm in thickness with large-scale structural consistency and integrity, which facilitates characteristic responses with highly sensitivity and reliability. Furthermore, the nanocomposite sensor shows simultaneous responses to multiple VOCs that commonly exist in daily life with an obvious suppression sensing for traditional flammable gases. Particularly, a detection limit of 0.1 ppm with a second-level response/recovery time can be achieved, which is beneficial for real-time air quality assessments. We proposed a heterojunction-induced sensing enhancement mechanism for the ZnO/WO3 nanocomposite film in which the formation of abundant heterojunctions between ZnO and WO3 NPs significantly increases the thickness of the electron depletion layer in the bulk film and improves the formation of active oxygen species on the surface, which is conducive to enhanced responses for reducing VOC gases. This work not only provides a simple approach for the fabrication of high-performance gas sensors but also opens an achievable avenue for air quality assessment based on VOC concentration detection.

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“…Photoionization detectors (PIDs) are widely used for detecting volatile organic compounds (VOCs). − Benefiting from its small footprint, lamp-based PIDs have been implemented in many field applications like environmental monitoring, industrial hygiene, healthcare, etc . ,,− …”

Section: Introductionmentioning

confidence: 99%

Ultrathin Silica Integration for Enhancing Reliability of Microfluidic Photoionization Detectors

et al. 2023

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Microfluidic photoionization detectors (μPIDs) based on silicon chips can rapidly and sensitively detect volatile compounds. However, the applications of μPID are limited by the manual assembly process using glue, which may outgas and clog the fluidic channel, and by the short lifetime of the vacuum ultraviolet (VUV) lamps (especially, argon lamps). Here, we developed a gold−gold cold welding-based microfabrication process to integrate ultrathin (10 nm) silica into μPID. The silica coating enables direct bonding of the VUV window to silicon under amicable conditions and works as a moisture and plasma exposure barrier for VUV windows that are susceptible to hygroscopicity and solarization. Detailed characterization of the silica coating was conducted, showing that the 10 nm silica coating allows 40−80% VUV transmission from 8.5 to 11.5 eV. It is further shown that the silica-protected μPID maintained 90% of its original sensitivity after 2200 h of exposure to ambient (dew point = 8.0 ± 1.8 °C), compared to 39% without silica. Furthermore, argon plasma inside an argon VUV lamp was identified as the dominant degradation source for the LiF window with color centers formation in UV−vis and VUV transmission spectra. Ultrathin silica was then also demonstrated effective in protecting the LiF from argon plasma exposure. Lastly, thermal annealing was found to bleach the color centers and restore VUV transmission of degraded LiF windows effectively, which will lead to future development of a new type of VUV lamp and the corresponding μPID (and PID in general) that can be mass produced with a high yield, a longer lifetime, and better regenerability.

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Characterization of a modular microfluidic photoionization detector

Cited by 12 publications

References 14 publications

Use of plasma electron spectroscopy method to detect hydrocarbons, alcohols, and ammonia in nonlocal plasma of short glow discharge

Use of plasma electron spectroscopy method to detect hydrocarbons, alcohols, and ammonia in nonlocal plasma of short glow discharge

Facile Synthesis of ZnO/WO3 Nanocomposite Porous Films for High-Performance Gas Sensing of Multiple VOCs

Ultrathin Silica Integration for Enhancing Reliability of Microfluidic Photoionization Detectors

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