Direct electrochemical characterization of superoxide anion production and its reactivity toward nitric oxide in solution

Selective and sensitive electrochemical biosensing of superoxide anion production by biological systems : a short overview of recent trends

“…The more efficient reported way in measuring in situ biological production of superoxide radicals by direct oxidation on non-enzymatic electrodes were based on building carbon microfibers [8,[40][41][42][43][44] with micrometric dimensions. The carbon fiber is sealed in a glass capillary by heating the glass to melt it around the fibre [40] or by using epoxy resin [8,41,42,44].…”

“…The carbon fiber is sealed in a glass capillary by heating the glass to melt it around the fibre [40] or by using epoxy resin [8,41,42,44]. The electrode was then polished prior to each run [40] or electrochemically pretreated [8,41].…”

“…The most recent trends of applications of the direct oxidation of superoxide anions on microfiber electrodes at 0.12V vs SCE, is related to the double determination of O 2 -and NO and the direct and simultaneous electrochemical measurements of both nitric oxide and superoxide anion evolution and reactivity in solution [8]. The use of the NO sensor provides the selective detection of NO without any interference of the superoxide enzymatic generator [8].…”

“…This has been allowed by the possibility to measure directly its concentration, particularly by electrochemical methods [5,6]. The quantification of the production of superoxide anions is hard to achieve because of their natural and/or catalyzed disproportionation by superoxide dismutase [7] and of their high reactivity towards other small molecules [2,8,9]. It appears that measuring O 2 -in biological models is very difficult because of its low concentration and fleeting existence.…”

Cell-compatible array of three-dimensional tip electrodes for the detection of nitric oxide release

“…Thus the process of electrode design, fabrication, electrode surface modification with electroactive catalysts, where applicable (Durst et al, 1997;Elliot and Murray, 1976;Kissinger and Heineman, 1996;Bard, 1983;Brett and Brett, 1980), and the geometry of the electrode, play significant roles in determining the magnitude of the current signals obtainable from a particular redox active biological species. For example, cylindrical electrodes (Privat et al, 1997;Malinski and Taha, 1992;Bedioui et al, 1996) are more commonly used for the detection of species in biological medium because of the larger surface area and consequently the higher current signal obtained as compared to disc-shaped electrodes.…”