| نویسندگان | سید مهدی قریشی-محسن بهپور-میترا مرتضوی-اسمائ خوبی |
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| نشریه | J MOL LIQ |
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| تاریخ انتشار | 2016-3-01 |
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| نمایه نشریه | ISI |
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چکیده مقاله
In the present study, the oxidation peak current of dopamine (DA) in a 0.2 M Britton–Robinson (B–R) buffer solutionwas
optimized by experimental design for its determination in the presence of tyrosine (Tyr) at the surface
of graphene oxide modified carbon paste electrode (CPE/GO). A central composite rotatable design (CCRD) and
response surface methodology (RSM) were used to evaluate the effects of the variables by the differential pulse
voltammetry (DPV) method. These variables include scan rate, step potential, modulation amplitude, graphene
oxide amount and pH. Characterizing of the CPE/GO was investigated by electrochemical impedance spectroscopy
(EIS), scanning electron microscopy (SEM) and cyclic voltammetry (CV) techniques. Also other voltammetric
techniques such as chronocoulometry and linear sweep voltammetry (LSV) were applied for electrochemical
studies of DA. Using these methods, diffusion coefficient (D = 9.2 × 10−5 cm2 s−1) and kinetic parameters
such as electron transfer coefficient (α = 0.6) and exchanging current density (j0 = 14.6 μA cm−2) of DA
were determined. Then, under the optimized conditions linear concentration range for DA was from 0.08 to
2.30 μM and the detection limit was found to be 8.60 nM. Finally CPE/GO could be employed for determination
of DA in real samples such as human blood plasma.
