title: In situ surface plasmon resonance measurements of self-assembled monolayers of ferrocenylalkylthiols under constant potentials.
abstract: A commercial system for surface plasmon resonance (SPR) possessing a batch-type flow channel has been simply modified so as to conduct in situ SPR measurements under polarization of an Au sensor chip at constant potentials. The modified instrument can monitor electrochemical reactions of monolayer materials with high stability and high reproducibility. The redox reaction of a self-assembled monolayer (SAM) of 6-ferrocenyl-1-hexanethiol (FcHT) induced the resonance angle shifts, the magnitudes of which accorded with the Nernst equation. The measurements in electrolyte solutions containing different electrolyte anions revealed that the SPR measurements detected ion pairing of electrolyte anions with oxidized FcHT. In cases of measurements in alkylsulfonic acid solution, simulation of the results based on the N-layer model has clarified that alkylsulfonate anions make an assembled layer on the FcHT SAM.
authors.affiliation: Department of Applied Chemistry, Graduate School of Engineering, Osaka University, Suita, Osaka, Japan.
authors.forename: Taro
authors.initials: T
authors.lastname: Uematsu
authors.forename: Susumu
authors.initials: S
authors.lastname: Kuwabata
mesh_terms: D004566:Electrodes; D005296:Ferrous Compounds / Q000737:chemistry*; D006046:Gold / Q000737:chemistry; D008567:Membranes, Artificial; D012680:Sensitivity and Specificity; D013438:Sulfhydryl Compounds / Q000737:chemistry*; D020349:Surface Plasmon Resonance / Q000295:instrumentation / Q000379:methods*; D013499:Surface Properties; D013997:Time Factors
chemical_list: D005296:Ferrous Compounds; D008567:Membranes, Artificial; D013438:Sulfhydryl Compounds; D006046:Gold