title: Synthesis and characterization of ferrocene modified Fe3O4@Au magnetic nanoparticles and its application.
abstract: A novel dopamine sensor was fabricated by forming the 6-ferrocenylhexanethiol (HS(CH(2))(6)Fc) functionalized Fe(3)O(4)@Au nanoparticles (NPs) films on the surface of a carbon paste electrode with the aid of a permanent magnet. HS(CH(2))(6)Fc, which acted as the redox mediator, was self-assembled to Fe(3)O(4)@Au NPs via Au-S bond. Transmission electron microscopy, UV-visible absorption spectroscopy, Fourier transform infrared spectra, and cyclic voltammetry were used to characterize the properties of the Fe(3)O(4)@Au NPs/HS(CH(2))(6)Fc nanocomposite. It is shown that the prepared ferrocene-functionalized Fe(3)O(4)@Au NPs composite shuttled electrons between analyte and electrode, increased the mediator loading, and more importantly prevented the leakage of the mediator during measurements, which resulted in the substantially enhanced stability and reproducibility of the modified electrode. The electrooxidation of dopamine could be catalyzed by Fc/Fc(+) couple as a mediator and had a higher electrochemical response due to the unique performance of Fe(3)O(4)@Au NPs. The nanocomposite modified electrode exhibited fast response (3 s) and the linear range was from 2.0x10(-6) to 9.2x10(-4) M with a detection limit of 0.64 microM. This immobilization approach effectively improved the stability of the electron transfer mediator and is promising for construction of other sensors and bioelectronic devices.
authors.affiliation: Department of Chemistry, Nanchang University, Xue Fu Da Dao 999, Nanchang 330031, China. jdqiu@ncu.edu.cn, qiujianding@163.com
authors.forename: Jian-Ding
authors.initials: JD
authors.lastname: Qiu
authors.forename: Meng
authors.initials: M
authors.lastname: Xiong
authors.forename: Ru-Ping
authors.initials: RP
authors.lastname: Liang
authors.forename: Hua-Ping
authors.initials: HP
authors.lastname: Peng
authors.forename: Fen
authors.initials: F
authors.lastname: Liu
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation*; D004298:Dopamine / Q000032:analysis*; D004563:Electrochemistry / Q000295:instrumentation*; D004566:Electrodes; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005290:Ferric Compounds / Q000737:chemistry*; D005296:Ferrous Compounds / Q000737:chemistry*; D006046:Gold / Q000737:chemistry; D008280:Magnetics / Q000295:instrumentation*; D000075163:Metallocenes; D053758:Nanoparticles / Q000737:chemistry*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D005290:Ferric Compounds; D005296:Ferrous Compounds; D000075163:Metallocenes; C000499:ferric oxide; D006046:Gold; C004998:ferrocene; D004298:Dopamine