title: 3-Mercaptopropylphosphonic acid modified gold electrode for electrochemical detection of dopamine.
abstract: 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.
authors.affiliation: State Key Laboratory of Coordination Chemistry, Coordination Chemistry Institute, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, PR China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Chen
authors.forename: Li-Rong
authors.initials: LR
authors.lastname: Guo
authors.forename: Wei
authors.initials: W
authors.lastname: Chen
authors.forename: Xiao-Jing
authors.initials: XJ
authors.lastname: Yang
authors.forename: Bo
authors.initials: B
authors.lastname: Jin
authors.forename: Li-Min
authors.initials: LM
authors.lastname: Zheng
authors.forename: Xing-Hua
authors.initials: XH
authors.lastname: Xia
mesh_terms: 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
chemical_list: C541098:3-mercaptopropylphosphonic acid; D015335:Molecular Probes; D063065:Organophosphonates; D013438:Sulfhydryl Compounds; D006046:Gold; D004298:Dopamine