Nitrogen Microplasma Generated in Chip-Based Ingroove Glow Discharge Device for Detection of Organic Fragments by Optical Emission Spectrometry

Abstract

In this study, nitrogen was successfully used to maintain the microplasma discharge to excite and detect organic compounds for the first time. A new nitrogen glow discharge microplasma-generated in-chip-based ingroove device was developed and applied as the excitation source for optical emission spectrometry. The unique ingroove design of the discharge chamber can provide good stability and sensitivity for nitrogen microplasma to detect trace organic samples. Unlike argon/helium microplasmas, the nitrogen microplasma has a strict demand on the material of electrodes, especially cathodes. We tested the effects of four common electrode materials from various aspects and obtained the most appropriate material for nitrogen glow discharge, namely, platinum. We also studied the excitation and detection mechanism of organic compounds in nitrogen microplasma and confirmed that the main means of excitation in nitrogen plasma was through energy transfer rather than penning ionization. Several organic compounds were directly injected and detected in the optimized working conditions with the limits of detection at the hundreds of picograms level. Because of the portable nitrogen generators handily and commercially available, this detection system with nitrogen as the discharge gas can overcome the limitation of noble gas supply. In addition, the advantages of small size, low energy consumption, good stability, and reproducibility demonstrate that the nitrogen ingroove microplasma source can be applied in a portable detector for on-site and real-time spectrometry detection.

Planar microplasma optical emission gas spectroscopy based on selective growth of ZnO nanowires

“…The intensity of the microplasma which is repeated 3 times for different gases Applying the planar design with the lithography process for electrodes fabrication results in fabricate electrodes with very small and precise gap width which is much less compared to vertical designs with around 500 μm gap size [9,18]. Selective growth of high aspect ratio ZnO nanowires on electrodes, which is a novel idea in microplasma systems for optical emission spectroscopy purpose, not only reduces the electrodes gap size (about 4-10 μm), but also enhances the local electric field and consequently reduces the ionization voltage for microplasma generation.…”

“…On the other hand, optical emission spectroscopy is a fast, unique, real-time and non-destructive technique to analyze gas species and their radiation spectrum [15,16]. A combination of microplasma devices with emission spectroscopy can act as a prominent method for gas detection purposes adding excellent selectivity to the system without raising too much in cost [17,18]. In addition, microplasma emission spectroscopy devices have some other advantages such as non-complexity, working at room temperature, capability for real time and portable usage, and lack of requirement for vacuum instruments compared to powerful gas analyzers like gas chromatography/mass spectroscopy [GC-MS] and inductively coupled plasma atomic emission spectrometry [9,18].…”

Detection of sulfur mustard simulants using the microwave atmospheric pressure plasma optical emission spectroscopy method

“…Up to now, many types of APP sources have been developed and used for the trace analysis, including (but not limited to) dielectric barrier discharge (DBD) (Meyer et al, 2012;Jiang et al, 2016;Han et al, 2018), glow discharge (Meng and Duan, 2015;Zhu et al, 2018), electrolyte cathode discharge (Yuan et al, 2021), mini-point discharge (Li et al, 2018;Yang et al, 2021), and microwave (MW) discharge (Pohl et al, 2008;Yuan et al, 2016;Borowska et al, 2019;Jung et al, 2019;Williams et al, 2019;Müller et al, 2020;Akhdhar et al, 2021). Compared with other APP sources, MW discharge has a relatively high power density (i.e., a strong dissociation ability) and a large reaction region (i.e., a long residence time for agents), and a highly purified reaction environment, eliminating any contamination due to the metal electrode, could be obtained, showing a promising future for trace detection of WCAs.…”

Microplasma-based flowing atmospheric-pressure afterglow (FAPA) source for ambient desorption-ionization mass spectrometry

“…Microplasmas are discharges confined to a size below 1 mm in at least one dimension [22], and are used in a variety of applications including detectors [23,24], biomedical devices [25], and lab-on-a-chip technology [26]. Microplasmas possess several properties that make them of interest for ADIMS.…”