Reactive oxygen species formation at Pt nanoparticles revisited by electron paramagnetic resonance and electrochemical analysis

Hartog, Stephan den; Samanipour, Mohammad; Ching, H. Y. Vincent; Doorslaer, Sabine Van; Breugelmans, Tom; Hubin, Annick; Ustarroz, Jon

doi:10.1016/j.elecom.2020.106878

Cited by 11 publications

(10 citation statements)

References 35 publications

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“…Figure 4 d shows that the concentration of OH• was around 1.27 μM under a 1-mm gap which is significantly higher than that of the treated one with a 5-mm gap. It is essential to know that the DMPO-OH signal originates from two different scenarios: a direct reaction between DMPO and OH• and a reaction between DMPO and OOH• producing DMPO-OOH, which further decomposes into DMPO-OH due to a short half-life of 1 min [ 33 ]. Thus, the origin of DMPO-OH was determined with different scavengers (D-mannitol and superoxide dismutase (SOD)) to analyze the plasma-induced liquid chemistry.…”

Section: Resultsmentioning

confidence: 99%

The Effect of Gap Distance between a Pin and Water Surface on the Inactivation of Escherichia coli Using a Pin-to-Water Plasma

Lim

Hong

Kim

et al. 2022

IJMS

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Atmospheric plasmas have been applied for the inactivation of microorganisms. Industrials demand to investigate the relation of the key reactive species induced by plasmas and the operating parameters including boundary conditions in order to control plasma treatment processes. In this study, we investigated the effect of gap distance between a pin-electrode and water surface on inactivation efficacy. When the gap distance decreased from 5 mm to 1 mm, the reduction of Escherichia coli (E. coli) was increased to more than 4 log CFU/mL. The reactive oxygen species measured optically and spectrophotometrically were influenced by gap distance. The results from electron spin resonance (ESR) analysis showed that the pin-to-water plasma generated hydroxyl radical (OH•) and singlet oxygen (1O2) in the water and superoxide radical (O2−•) served as a precursor of OH•. The inactivation of E. coli was significantly alleviated by sodium azide (1O2 scavenger), indicating that 1O2 contributes the most to bacterial inactivation. These findings provide a potentially effective strategy for bacterial inactivation using a pin-to-water plasma.

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Section: Resultsmentioning

confidence: 99%

The Effect of Gap Distance between a Pin and Water Surface on the Inactivation of Escherichia coli Using a Pin-to-Water Plasma

Lim

Hong

Kim

et al. 2022

IJMS

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“…Nevertheless, this technique is still extensively used in case of heterogeneous catalytic ozonation to identify HO• and O2•on graphene doped with N, P, B and S 116 . Recent investigations of the electroreduction of oxygen on Pt nanoparticles also identified HO• as unique reaction intermediates by coupling spin-trap EPR and electrochemical analysis 117 .…”

Section: Detection and Quantification Of Reactive Radical Oxygen Speciesmentioning

confidence: 99%

“…•− on graphene doped with N, P, B, and S. 116 Recent investigations of the electroreduction of oxygen on Pt nanoparticles also identified HO • as unique reaction intermediates by coupling spin-trap EPR and electrochemical analysis. 117 In situ EPR measurements have been also implemented to clarify the heterogeneously catalyzed decomposition of hydrogen peroxide on cobalt and copper hydrogel containing Cu(II) and Co(II) active centers coordinated to aliphatic amine, Nheterocycle, or carboxylic acid ligands. Reactive oxygen species from H 2 O 2 have been characterized by spin trapping with DMPO.…”

Section: From Kinetics and Reaction Mechanisms To Reactor Design In C...mentioning

confidence: 99%

Recent Progress and Prospects in Catalytic Water Treatment

et al. 2021

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HAL is a multi-disciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L'archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.

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“…This is somewhat surprising, especially as EPR is the 'go-to' method for confirmation of the existence of electrochemically generated HO˙. [13][14][15][37][38][39] As the potential required to electrochemically generate HO˙ in aqueous solution is so high (eq. 1), and water is present in excess, concerns must be raised over the roles of eqs.…”

Section: Introductionmentioning

confidence: 99%

“…22,42 A very popular spin trap for electrochemically generated HO˙ detection is the nitrone based, 5,5dimethyl-1-pyrroline N-oxide (DMPO). [13][14][15]37,39,43 The DMPO adducts possess a β-hydrogen enabling the discrimination of small radical species through the different observed splitting parameters. 44 Even though the first report of the electrochemical oxidation of DMPO was published in the 1980s 42 using a platinum (Pt) electrode in a non-aqueous solvent, the potential issues of using DMPO for HO˙ electrochemical-EPR (EC-EPR) detection has still not been widely acknowledged in the EC-EPR community.…”

Section: Introductionmentioning

confidence: 99%

Electron Paramagnetic Resonance for the Detection of Electrochemically Generated Hydroxyl Radicals: Issues Associated with Electrochemical Oxidation of the Spin Trap

Braxton

Fox

Breeze

et al. 2022

Preprint

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For the detection of electrochemically produced hydroxyl radicals (OH˙) from the oxidation of water, electron paramagnetic resonance spectroscopy (EPR) in combination with spin trap labels is a popular technique. Here we show that quantification of the true concentration of OH˙ generated from water oxidation via electrochemical (EC)-EPR is unlikely. This is primarily due to the spin trap oxidising at potentials less positive than water and resulting in the same spin trap adduct as is formed from the solution reaction of OH˙ with the spin trap. We illustrate this through consideration of 5,5-dimethyl-1-pyrroline N-oxide (DMPO) to spin trap OH˙. DMPO oxidation on a boron doped diamond (BDD) electrode in stationary solution occurs at a peak current potential of +1.90 V vs SCE, water oxidation commences at +2.35 V vs SCE. EC-EPR spectra shows signatures due to the hydroxyl spin adduct (DMPO-OH˙) at potentials lower than the thermodynamic standard water/HO˙ potential and in the region for DMPO oxidation. Increasing the potential into the water oxidation region, surprisingly, shows a lower DMPO-OH˙ concentration than when the potential is in the DMPO oxidation region. This behavior is attributed to further oxidation of DMPO-OH˙, production of fouling products on the electrode surface and bubble formation. Radical scavengers (ethanol) and other spin traps, here N-tert-butyl-α-phenylnitrone (PBN), α-(4-pyridyl N-oxide)-N-tert-butylnitrone (POBN) and 2-methyl-2-nitrosopropane dimer (MNP), also show oxidation signals less positive than that of water. However, by monitoring ethanol-DMPO adduct versus DMPO-OH˙ product distributions as a function of applied potential, it is possible to identify the potential at which HO˙ generation via water oxidation starts to dominate.

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Reactive oxygen species formation at Pt nanoparticles revisited by electron paramagnetic resonance and electrochemical analysis

Cited by 11 publications

References 35 publications

The Effect of Gap Distance between a Pin and Water Surface on the Inactivation of Escherichia coli Using a Pin-to-Water Plasma

The Effect of Gap Distance between a Pin and Water Surface on the Inactivation of Escherichia coli Using a Pin-to-Water Plasma

Recent Progress and Prospects in Catalytic Water Treatment

Electron Paramagnetic Resonance for the Detection of Electrochemically Generated Hydroxyl Radicals: Issues Associated with Electrochemical Oxidation of the Spin Trap

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