title: Cysteamine capped CdS quantum dots as a fluorescence sensor for the determination of copper ion exploiting fluorescence enhancement and long-wave spectral shifts.
abstract: We described a turn-on fluorescence sensor for the determination of Cu(2+) ions, utilizing the quantum confinement effect of cadmium sulfide quantum dots capped with cysteamine (Cys-CdS QDs). The fluorescence intensity of the Cys-CdS QDs was both enhanced and red shifted (from blue-green to yellow) in the presence of Cu(2+). Fluorescence enhancement was linearly proportional to the concentration of Cu(2+) in the concentration range 2 to 10μM. Other cations at the same concentration level did not significantly change the intensity and spectral maxima of Cys-CdS QDs, except Ag(+). The limit of detection was 1.5μM. The sensor was applied to the determination of Cu(2+) in (spiked) real water samples and gave satisfactory results, with recoveries ranging from 96.7 to 108.2%, and with RSDs ranging from 0.3 to 2.6%.
authors.affiliation: Department of Chemistry, Faculty of Science, Khon Kaen University, Khon Kaen 40002, Thailand.
authors.forename: Chanida
authors.initials: C
authors.lastname: Boonmee
authors.affiliation: Department of Chemistry, Faculty of Science, Khon Kaen University, Khon Kaen 40002, Thailand; Faculty of Science and Engineering, Kasetsart University Chalermphrakiat Sakon Nakhon Province Campus, Sakon Nakhon 47000, Thailand.
authors.forename: Tuanjai
authors.initials: T
authors.lastname: Noipa
authors.affiliation: Department of Chemistry, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand.
authors.forename: Thawatchai
authors.initials: T
authors.lastname: Tuntulani
authors.affiliation: Department of Chemistry, Faculty of Science, Khon Kaen University, Khon Kaen 40002, Thailand; Materials Chemistry Research Center, Department of Chemistry and Center of Excellence for Innovation in Chemistry, Faculty of Science, Khon Kaen University, Khon Kaen 40002, Thailand. Electronic address: wittayange@kku.ac.th.
authors.forename: Wittaya
authors.initials: W
authors.lastname: Ngeontae
keywords: Chemical sensors; Copper(II) ion; Fluorescence sensors; Optical nanomaterials; Quantum dots