3-Mercaptopropylphosphonic acid modified gold electrode for electrochemical detection of dopamine.
It is reported for the first time that the phosphonic acid terminated self-assembled layers assembled on a gold surface could be used as a functional interface to sensitively and selectively detect dopamine (DA) in the presence of highly concentrated ascorbic acid (AA). X-ray photoelectron spectroscopic (XPS) and reductive desorption measurements proved that the 3-mercaptopropylphosphonic acid [HS-(CH(2))(3)-PO(3)H(2), MPPA] was successfully immobilized on the gold surface via S-Au bond. Making use of the electrostatic interactions between the negatively charged phosphonic acid groups on the electrode surface and DA and AA, the MPPA modified electrode was successfully used to electrochemically discriminate between DA and AA. Cyclic voltammetry measurements shown that the MPPA modified electrodes almost completely inhibited the electrochemical reaction of AA. Therefore, DA can be selectively and sensitively determined by using the differential pulse voltammetry technique although high concentration of AA is present.
Chen
Yu
Y
State Key Laboratory of Coordination Chemistry, Coordination Chemistry Institute, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, PR China.
Guo
Li-Rong
LR
Chen
Wei
W
Yang
Xiao-Jing
XJ
Jin
Bo
B
Zheng
Li-Min
LM
Xia
Xing-Hua
XH
D004298:Dopamine / Q000032:analysis* / Q000737:chemistry*; D055664:Electrochemical Techniques / Q000379:methods*; D004563:Electrochemistry; D004566:Electrodes; D006046:Gold / Q000737:chemistry*; D015335:Molecular Probes / Q000032:analysis / Q000737:chemistry; D063065:Organophosphonates / Q000737:chemistry*; D010084:Oxidation-Reduction; D013057:Spectrum Analysis; D013438:Sulfhydryl Compounds / Q000737:chemistry*; D013499:Surface Properties
C541098:3-mercaptopropylphosphonic acid; D015335:Molecular Probes; D063065:Organophosphonates; D013438:Sulfhydryl Compounds; D006046:Gold; D004298:Dopamine