Scanning Electrochemical Microscopy Studies of Glutathione-Modified Surfaces. An Erasable and Sensitive-to-Reactive Oxygen Species Surface

Langmuir ◽  
2011 ◽  
Vol 27 (17) ◽  
pp. 11206-11211 ◽  
Author(s):  
Alina Latus ◽  
Jean-Marc Noël ◽  
Elena Volanschi ◽  
Corinne Lagrost ◽  
Philippe Hapiot
Keyword(s):  
Reactive Oxygen Species ◽  
Reactive Oxygen ◽  
Scanning Electrochemical Microscopy ◽  
Oxygen Species ◽  
Modified Surfaces ◽  
Electrochemical Microscopy

Redox reactions of reactive oxygen species in aqueous solutions as the probe for scanning electrochemical microscopy of single live T24 cells

2010 ◽  
Vol 88 (6) ◽  
pp. 569-576 ◽  
Author(s):  
Xiaocui Zhao ◽  
Mengni Zhang ◽  
Yitao Long ◽  
Zhifeng Ding
Keyword(s):  
Reactive Oxygen Species ◽  
Hydrogen Peroxide ◽  
Aqueous Solutions ◽  
Redox Reactions ◽  
Reactive Oxygen ◽  
Scanning Electrochemical Microscopy ◽  
Electrochemical Technique ◽  
Oxygen Species ◽  
T24 Cells ◽  
Electrochemical Microscopy

The redox reactions of two main components of reactive oxygen species (ROS), superoxide and hydrogen peroxide, along with oxygen in aqueous solutions were investigated using a conventional electrochemical technique, differential pulse voltammetry (DPV). Superoxide undergoes oxidation at a Pt working electrode biased at 0.055 V versus Ag/AgCl, while hydrogen peroxide can be oxidized and reduced at 0.817 and –0.745 V, respectively. Oxygen in the solutions is reduced at the electrode with an applied potential of –0.455 V. Based on these results, hydrogen peroxide and superoxide released from live cells can be successfully monitored, identified, and mapped using scanning electrochemical microscopy (SECM) at different potentials. Single human bladder (T24) cells were imaged using a 5 μm diameter SECM probe biased at –0.400, –0.600, and –0.800 V. Oxygen reduction that seems an interference can be discriminated from that of hydrogen peroxide by means of SECM.

scholarly journals Reactive oxygen species formed in organic lithium–oxygen batteries

2016 ◽  
Vol 18 (16) ◽  
pp. 10774-10780 ◽  
Author(s):  
Patrick Schwager ◽  
Saustin Dongmo ◽  
Daniela Fenske ◽  
Gunther Wittstock
Keyword(s):  
Reactive Oxygen Species ◽  
Fluorescence Microscopy ◽  
Reactive Oxygen ◽  
Scanning Electrochemical Microscopy ◽  
Oxygen Species ◽  
Organic Electrolytes ◽  
Lithium Oxygen Batteries ◽  
Electrochemical Microscopy ◽  
Discharge Reaction

The generation of reactive oxygen species has been assumed to occur during the charging reaction of lithium-oxygen batteries with organic electrolytes. Here we show independently by fluorescence microscopy and scanning electrochemical microscopy that superoxide is also formed and released into the solution during the discharge reaction.

Mitochondria as a source of reactive oxygen species

2009 ◽  
pp. c3 ◽  
Author(s):  
Helena M. Cochemé ◽  
Michael P. Murphy
Keyword(s):  
Reactive Oxygen Species ◽  
Reactive Oxygen ◽  
Oxygen Species

Clinical aspects of reactive oxygen and nitrogen species

2004 ◽  
Vol 71 ◽  
pp. 121-133 ◽  
Author(s):  
Ascan Warnholtz ◽  
Maria Wendt ◽  
Michael August ◽  
Thomas Münzel
Keyword(s):  
Oxidative Stress ◽  
Reactive Oxygen Species ◽  
Risk Factor ◽  
Endothelial Dysfunction ◽  
Vascular Tissue ◽  
Rapid Development ◽  
Reactive Oxygen ◽  
Clinical Aspects ◽  
No Production ◽  
Oxygen Species

Endothelial dysfunction in the setting of cardiovascular risk factors, such as hypercholesterolaemia, hypertension, diabetes mellitus and chronic smoking, as well as in the setting of heart failure, has been shown to be at least partly dependent on the production of reactive oxygen species in endothelial and/or smooth muscle cells and the adventitia, and the subsequent decrease in vascular bioavailability of NO. Superoxide-producing enzymes involved in increased oxidative stress within vascular tissue include NAD(P)H-oxidase, xanthine oxidase and endothelial nitric oxide synthase in an uncoupled state. Recent studies indicate that endothelial dysfunction of peripheral and coronary resistance and conductance vessels represents a strong and independent risk factor for future cardiovascular events. Ways to reduce endothelial dysfunction include risk-factor modification and treatment with substances that have been shown to reduce oxidative stress and, simultaneously, to stimulate endothelial NO production, such as inhibitors of angiotensin-converting enzyme or the statins. In contrast, in conditions where increased production of reactive oxygen species, such as superoxide, in vascular tissue is established, treatment with NO, e.g. via administration of nitroglycerin, results in a rapid development of endothelial dysfunction, which may worsen the prognosis in patients with established coronary artery disease.

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