Electrochemical behavior of dopamine in the presence of citrate: Reaction mechanism

Winter, Eduardo; Codognoto, Lúcia; Rath, Susanne

doi:10.1016/j.electacta.2005.06.014

Cited by 12 publications

(6 citation statements)

References 18 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…[5][6][7][8][9][10][11][12][13][14][15] Because of dopamines key involvement in neural processes, there is keen interest in in vivo voltammetric monitoring of dopamine in mammalian brains. [16] The voltammetric mechanism involves an adsorption/desorption process at carbon [17][18][19][20][21][22][23][24] and metallic electrodes, [21,[25][26][27][28] which aids in the voltammetric detection limits. Pure carbon fibers give excellent detection limits, [17][18][19][20][21] and there have been extensive studies that use surface-modified electrodes to improve the detection of dopamine and reduce the interference from other biological molecules that are easily oxidized, such as ascorbic acid.…”

mentioning

confidence: 99%

The Effect of the Buffering Capacity of the Supporting Electrolyte on the Electrochemical Oxidation of Dopamine and 4‐Methylcatechol in Aqueous and Nonaqueous Solvents

Chen

Tai

Webster

2011

Chemistry An Asian Journal

View full text Add to dashboard Cite

Dopamine was electrochemically oxidized in aqueous solutions and in the organic solvents N,N-dimethyl-formamide and dimethylsulfoxide containing varying amounts of supporting electrolyte and water, to form dopamine ortho-quinone. It was found that the electrochemical oxidation mechanism in water and in organic solvents was strongly influenced by the buffering properties of the supporting electrolyte. In aqueous solutions close to pH 7, where buffers were not used, the protons released during the oxidation process were able to sufficiently change the localized pH at the electrode surface to reduce the deprotonation rate of dopamine ortho-quinone, thereby slowing the conversion into leucoaminochrome. In N,N-dimethylformamide and dimethylsulfoxide solutions, in the absence of buffers, dopamine was oxidized to dopamine ortho-quinone that survived without further reaction for several minutes at 25 °C. The voltammetric data obtained in the organic solvents were made more complicated by the presence of HCl in commercial sources of dopamine, which also underwent an oxidation process.

show abstract

mentioning

confidence: 99%

The Effect of the Buffering Capacity of the Supporting Electrolyte on the Electrochemical Oxidation of Dopamine and 4‐Methylcatechol in Aqueous and Nonaqueous Solvents

Chen

Tai

Webster

2011

Chemistry An Asian Journal

View full text Add to dashboard Cite

show abstract

“…In 2006, the electrochemical (1) G et (2) Fullerenes (C n ) with NT(s); 1-4 Fig. 3 The surfaces of the free energy of electron transfer ΔG et(n) and ΔG et(n) # (n=1-4) between neurotransmitters (NTs) acetylcholine (AC) 1, dopamine (DP) 2, serotonin (SE) 3, and epinephrine (EP) 4 and fullerenes behavior at a mercury electrode of DA in the presence of citrate was investigated in aqueous solution, using cyclic voltammetry and alternating current polarography by Rath et al [68]. In 2001, an electrochemical sensor for the determination of serotonin in urine was prepared using Ni(II)-phthalocyanine and Nafion to modify the surface of carbon fiber microelectrode.…”

Section: Discussionmentioning

confidence: 99%

“…It is well known that electrochemical oxidation of phenolic compounds generally produces unstable phenoxy radicals that readily polymerize to passivate the surface of platinum electrodes [67][68][69][70][71][72][73][74][75] because the phenoxy radicals can interact with each other or with another phenol monomer to give rise to a strongly adherent insulating film with a thickness of 100-1000 Å [70][71][72] and with irregular pores [67,68,74,75]. In 2006, the oxidation potential of acetylcholine was measured by the use of nano-nickel oxide/nickel incorporated nickel composite coating by Shibli et al [76].…”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Theoretical study of electron transfer process between fullerenes and neurotransmitters; acetylcholine, dopamine, serotonin and epinephrine in nanostructures [neurotransmitters].C n complexes

et al. 2015

View full text Add to dashboard Cite

Neurotransmitters are the compounds which allow the transmission of signals from one neuron to the next across synapses. They are the brain chemicals that communicate information throughout brain and body. Fullerenes are a family of carbonallotropes, molecules composed entirely of carbon, that take the forms of spheres, ellipsoids, and cylinders. Various empty carbon fullerenes (Cn) with different carbon atoms have been obtained and investigated. Topological indices have been successfully used to construct effective and useful mathematical methods to establish clear relationships between structural data and the physical properties of these materials. In this study, the number of carbon atoms in the fullerenes was used as an index to establish a relationship between the structures of neurotransmitters (NTs) acetylcholine (AC) 1, dopamine (DP) 2, serotonin (SE) 3, and epinephrine (EP) 4 as the well-known redox systems and fullerenes C n (n = 60, 70, 76, 82, and 86) which create [NT].Cn; A-1 to A-5 up to D-1 to D-5. The relationship between the number of carbon atoms and the free energy of electron transfer (ΔG et(n); n = 1-4) is assessed using the Rehm-Weller equation for A-1 to A-5 up to D-1 to D-5 supramolecular [NT].Cn complexes. The calculations are presented for the four reduction potentials ( (Red.) E 1 to (Red.) E 4 ) of fullerenes C n . The results were used to calculate the four free energy values of electron transfer (ΔG et(1) to ΔG et(4)) of the supramolecular complexes A-1 to A-8 up to D-1 to D-8 for fullerenes C60 to C120. The first to fourth free activation energy values of electron transfer and the maximum wavelength of the electron transfers, ΔG (#) et(n) and λ et (n = 1-4), respectively, were also calculated in this study for A-1 to A-8 up to D-1 to D-8 in accordance with the Marcus theory.

show abstract

“…In acid pH, the species is mostly in the protonated form (DAH + ) [36,61]. In this way, the DAH + is oxidized to dopaminoquinone in a two-proton and two-electron mechanism [62,63] as represented in Fig. 6.…”

Section: Electrochemical Characterizationmentioning

confidence: 99%

Mesoporous silica xerogel modified with bridged ionic silsesquioxane used to immobilize copper tetrasulfonated phthalocyanine applied to electrochemical determination of dopamine

Deon

Caldas

Rosa

et al. 2014

J Solid State Electrochem

View full text Add to dashboard Cite

Silica xerogel was modified with an ionic s i l s e s q u i o x a n e c o n t a i n i n g t h e c a t i o n i c 1 , 4 -diazoniabicyclo[2.2.2]octane bridged group and it was used as matrix for immobilization of copper tetrasulfonated phthalocyanine, resulting in Si/Db/CuTsPc material. This material was characterized by ultraviolet-visible and infrared spectroscopy, elemental and thermogravimetric analyses, nitrogen adsorption-desorption isotherms, and scanning electron microscopy. The Si/Db/CuTsPc material was used to develop a carbon paste electrode for dopamine determination. The electrochemical behavior of dopamine was evaluated by cyclic voltammetry and chronoamperometry. The optimal experimental conditions were determined (pH=4.5 and oxygen atmosphere) using a 0.1 mol L −1 phosphate buffer solution. The carbon paste electrode modified with the Si/Db/CuTsPc material shows a linear response for current intensity with the dopamine concentration in the range of 0.010 to 0.107 mmol L −1 . The detection limit was 0.42 μmol L −1 , and the sensitivity was 7.15 μA (mmol L −1 ) −1 , making the system promising to be applied as electrochemical sensor for dopamine.

show abstract

Electrochemical behavior of dopamine in the presence of citrate: Reaction mechanism

Cited by 12 publications

References 18 publications

The Effect of the Buffering Capacity of the Supporting Electrolyte on the Electrochemical Oxidation of Dopamine and 4‐Methylcatechol in Aqueous and Nonaqueous Solvents

The Effect of the Buffering Capacity of the Supporting Electrolyte on the Electrochemical Oxidation of Dopamine and 4‐Methylcatechol in Aqueous and Nonaqueous Solvents

Theoretical study of electron transfer process between fullerenes and neurotransmitters; acetylcholine, dopamine, serotonin and epinephrine in nanostructures [neurotransmitters].C n complexes

Mesoporous silica xerogel modified with bridged ionic silsesquioxane used to immobilize copper tetrasulfonated phthalocyanine applied to electrochemical determination of dopamine

Contact Info

Product

Resources

About