Pulse Radiolysis Studies of Electron Transfer Reaction in Molecules of Biological Interest: I. The Reduction of a Disulfide Bridge by Peptide Radicals

1975 ◽  
Vol 64 (3) ◽  
pp. 452 ◽  
Author(s):  
M. Faraggi ◽  
J. L. Redpath ◽  
Y. Tal
Keyword(s):  
Electron Transfer ◽  
Pulse Radiolysis ◽  
Transfer Reaction ◽  
Disulfide Bridge ◽  
Electron Transfer Reaction ◽  
Biological Interest ◽  
Peptide Radicals

A pulse radiolysis study of the reactions of hydrogen atoms with dimethyl-, tetramethyl- and hexamethyl-substituted viologens

1984 ◽  
Vol 37 (8) ◽  
pp. 1579 ◽  
Author(s):  
NA McAskill
Keyword(s):  
Electron Transfer ◽  
Radical Cation ◽  
Pulse Radiolysis ◽  
Transfer Reaction ◽  
Electron Transfer Reaction ◽  
Methyl Groups ◽  
Transient Species ◽  
Hydrogen Atoms ◽  
Abstraction Reaction

The reactions of ·H, ·OH and e-aq with four viologens in aqueous solution were studied by spectrophotometry. With 1,1'-dimethyl-4,4'-bipyridinium dichloride, the main transient species caused by H reaction is the viologen radical cation formed by an electron-transfer reaction. Smaller amounts of a hydrogen-deficient radical are also formed by an abstraction reaction at one of the methyl groups together with a radical formed by addition of ·H to one of the rings. There is no evidence that a protonated radical cation species was formed. A similar pattern of reactivity is seen with 1,1',2,2'-tetra-methyl-4,4'-bipyridinium diperchlorate. However, the electron-transfer reaction is either absent in the case of 1,1',3,3'-tetramethyl-4,4'-bipyridinium diperchlorate or less important in 1,1',2,2',6,6'- hexamethyl-4,4'-bipyridinium dichloride, and the main initial transient is assigned to a hydrogen-deficient radical formed by an abstraction reaction at one of the ring methyl groups. The possible role of the hydrogen-deficient radical in reducing the loss of viologen observed in the photochemical splitting of water is discussed.

Generation of the C60 radical cation via electron transfer reaction. A pulse radiolysis study

1993 ◽  
Vol 203 (5-6) ◽  
pp. 555-559 ◽  
Author(s):  
Hui-qi Hou ◽  
Chang Luo ◽  
Zhao-xiang Liu ◽  
Dun-min Mao ◽  
Qi-zong Qin ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Radical Cation ◽  
Pulse Radiolysis ◽  
Transfer Reaction ◽  
Electron Transfer Reaction

scholarly journals Electron transfer studies of a conventional redox probe in human sweat and saliva bio-mimicking conditions

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
P. Krishnaveni ◽  
V. Ganesh
Keyword(s):  
Electron Transfer ◽  
Crystalline Phase ◽  
Liquid Crystalline ◽  
Transfer Reaction ◽  
Electron Transfer Reaction ◽  
Redox Couple ◽  
Liquid Crystalline Phase ◽  
Transfer Reactions ◽  
Redox Probe ◽  
Human Sweat

AbstractModern day hospital treatments aim at developing electrochemical biosensors for early diagnosis of diseases using unconventional human bio-fluids like sweat and saliva by monitoring the electron transfer reactions of target analytes. Such kinds of health care diagnostics primarily avoid the usage of human blood and urine samples. In this context, here we have investigated the electron transfer reaction of a well-known and commonly used redox probe namely, potassium ferro/ferri cyanide by employing artificially simulated bio-mimics of human sweat and saliva as unconventional electrolytes. Typically, electron transfer characteristics of the redox couple, [Fe(CN)6]3−/4− are investigated using electrochemical techniques like cyclic voltammetry and electrochemical impedance spectroscopy. Many different kinetic parameters are determined and compared with the conventional system. In addition, such electron transfer reactions have also been studied using a lyotropic liquid crystalline phase comprising of Triton X-100 and water in which the aqueous phase is replaced with either human sweat or saliva bio-mimics. From these studies, we find out the electron transfer reaction of [Fe(CN)6]3−/4− redox couple is completely diffusion controlled on both Au and Pt disc shaped electrodes in presence of sweat and saliva bio-mimic solutions. Moreover, the reaction is partially blocked by the presence of lyotropic liquid crystalline phase consisting of sweat and saliva bio-mimics indicating the predominant charge transfer controlled process for the redox probe. However, the rate constant values associated with the electron transfer reaction are drastically reduced in presence of liquid crystalline phase. These studies are essentially carried out to assess the effect of sweat and saliva on the electrochemistry of Fe2+/3+ redox couple.

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