Abatement of trichloroethylene using DBD plasma

Dielectric barrier discharge plasma was used to oxidize trichloroethylene (TCE) in 21% of O2 in carriers of N2 and He. The degradation products of TCE were analyzed using gas chromatography mass spectrometry. TCE was decomposed completely at optimum energy density of 260 and 300 J/l for He and N2, respectively and its conversion followed zero order reaction. The TCE removal efficiency is decreased in humid air due to interception of reactive intermediates by OH radicals

H2O/air plasma-functionalized carbon nanotubes decorated with MnO2 for glucose sensing

Multi-walled carbon nanotubes (MWCNTs) were functionalized using dielectric barrier discharge plasma in water vapor-saturated air at 70 °C. MnO2 was deposited on the MWCNTs by chronoamperometry, followed by glucose oxidase (GOx) immobilization, and the resulting GOx/MnO2/MWCNTs electrode was used for electrochemical detection of glucose. Structural, morphological, and elemental microanalysis was performed. Plasma-induced oxygen-based functional groups were confirmed on the MWCNT surfaces and improved their dispersion in aqueous solutions. The maximum amount of these groups was created at the optimum exposure time of 4 min. The GOx immobilized on the MnO2/MWCNTs hybrid showed a well-defined, reversible and surface-controlled redox wave around −0.45 V and a peak to peak separation of 0.04 V. The coefficient and rate constant for electron transfer of GOx were calculated as 0.41 and 1.08 s−1, respectively. The GOx/MnO2/MWCNT-modified electrode exhibited a linear behavior in the range of 0.1–3.2 mM glucose concentration with the competitive detection limit of 3.0 μM and a sensitivity of 24.2 μA mM−1 cm−2. This highly-stable glucose sensing electrode retained more than 76% of its initial faradic current value after 71 days. These results are relevant to the development of next-generation glucose sensors for diverse health- and food-related applications