Eu（ Ⅲ ） can be utilized as an indirect electrochemical probe to investigate the interaction of bio-molecules such as DOPA and Dopamine with Ca（ Ⅱ ） in vitro. The interaction of DOPA and Dopamine with Eu（ Ⅲ ）...Eu（ Ⅲ ） can be utilized as an indirect electrochemical probe to investigate the interaction of bio-molecules such as DOPA and Dopamine with Ca（ Ⅱ ） in vitro. The interaction of DOPA and Dopamine with Eu（ Ⅲ ）-Eu（ Ⅱ ） redox pair was investigated by electrochemical techniques. Both the neurotransmitters are structurally related and undergo interaction with Eu （Ⅲ ）. Eu （ Ⅲ ） coordinates with DOPA and Dopamine through five-member chelate tings via carboxylic oxygen and amino nitrogen. The electrode kinetic parameters viz, transfer coefficient （αna）, diffusion coefficient （D）, forward heterogeneous rate constant （ k^0 fh） were evaluated for Eu（ Ⅲ ）-DOPA/Eu（ Ⅲ ）-Dopamine. The results obtained were used to investigate the nature of interaction of Eu （Ⅲ） with muhi-donor biomolecules. The possible mechanism was also proposed.展开更多
The divalent state of Ln（III） ions has attracted much interest because of their ability to serve isomorphously in many biological system of divalent Ca（II） ion. Therefore, present paper deals with the study of div...The divalent state of Ln（III） ions has attracted much interest because of their ability to serve isomorphously in many biological system of divalent Ca（II） ion. Therefore, present paper deals with the study of divalent state of Eu（III） and Nd（III） ions in non-aqueous medium. In present study, cyclic voltammetry and chronopotentiometry were utilized to establish the divalent state of Eu（III） and Nd（III） ions. The cyclic voltammetric technique showed two-step reduction process at cathode for both Ln（III） ions under specified experimental conditions and chronopotentiometric method also showed two different transition times （r）. Looking to the shape of cyclic voltammogram we calculated het- erogeneous forward rate constant （K^fh, cm/s） and diffusion coefficient （D, cm2/s） for both ions, which suggested that sweep rate had great ef- fect on the shape of cyclic voltammogram of Eu（III） and Nd（III） ions. The result of chronopotentiometry also suggested that stable divalent states of Eu（III） and Nd（III） ions existed with chronopotentiogram with two distinct transition times. The diffusion coefficients （D, cm2/s） were calculated from Sand equation. The diffusion coefficients of both techniques were compared and the results suggested that the system at electrode surface was changing from being reversible to irreversible.展开更多
基金Foundation ite m:Project supported by DST(SP/S1/F03/98)
文摘Eu（ Ⅲ ） can be utilized as an indirect electrochemical probe to investigate the interaction of bio-molecules such as DOPA and Dopamine with Ca（ Ⅱ ） in vitro. The interaction of DOPA and Dopamine with Eu（ Ⅲ ）-Eu（ Ⅱ ） redox pair was investigated by electrochemical techniques. Both the neurotransmitters are structurally related and undergo interaction with Eu （Ⅲ ）. Eu （ Ⅲ ） coordinates with DOPA and Dopamine through five-member chelate tings via carboxylic oxygen and amino nitrogen. The electrode kinetic parameters viz, transfer coefficient （αna）, diffusion coefficient （D）, forward heterogeneous rate constant （ k^0 fh） were evaluated for Eu（ Ⅲ ）-DOPA/Eu（ Ⅲ ）-Dopamine. The results obtained were used to investigate the nature of interaction of Eu （Ⅲ） with muhi-donor biomolecules. The possible mechanism was also proposed.
文摘The divalent state of Ln（III） ions has attracted much interest because of their ability to serve isomorphously in many biological system of divalent Ca（II） ion. Therefore, present paper deals with the study of divalent state of Eu（III） and Nd（III） ions in non-aqueous medium. In present study, cyclic voltammetry and chronopotentiometry were utilized to establish the divalent state of Eu（III） and Nd（III） ions. The cyclic voltammetric technique showed two-step reduction process at cathode for both Ln（III） ions under specified experimental conditions and chronopotentiometric method also showed two different transition times （r）. Looking to the shape of cyclic voltammogram we calculated het- erogeneous forward rate constant （K^fh, cm/s） and diffusion coefficient （D, cm2/s） for both ions, which suggested that sweep rate had great ef- fect on the shape of cyclic voltammogram of Eu（III） and Nd（III） ions. The result of chronopotentiometry also suggested that stable divalent states of Eu（III） and Nd（III） ions existed with chronopotentiogram with two distinct transition times. The diffusion coefficients （D, cm2/s） were calculated from Sand equation. The diffusion coefficients of both techniques were compared and the results suggested that the system at electrode surface was changing from being reversible to irreversible.
