title: Synthesis of 2-Mercaptonicotinic Acid-Capped CdSe Quantum Dots and its Application to Spectrofluorometric Determination of Cr(VI) in Water Samples.
abstract: The CdSe quantum dots (QDs) capped with 2-mercaptonicotinic acid (H2MN) were prepared through a controllable process at 80 °C. The prepared QDs were characterized by XRD, TEM, IR, UV-Vis and fluorescence (FL) techniques. It was found that the QDs were nearly mono-disperse with the diameters in the range of 8-10 nm. These QDs are capable to exhibit strong FL even in concentrated acidic media. They exhibit an enhanced fluorescence in the presence of Cr(VI), which was used for the determination of Cr(VI) in water samples. The linear range was found to be 1 × 10(-7)-6.0 × 10(-6) M with the RSD and DL of 0.92 % and 5 × 10(-8) M, respectively. Except that Ca(2+) and Fe(3+) which can be eliminated through a simple precipitation process, the other co-existent ions present in natural water were not interfered. The recoveries obtained for the added amounts of Cr(VI) were in the range of 96.9-103.2 %, which denote on application of the method, satisfactorily.
authors.affiliation: Department of Chemistry, Birjand University, Birjand, Iran. mshosseini1336@yahoo.com.
authors.forename: Mohammad Saeid
authors.initials: MS
authors.lastname: Hosseini
authors.affiliation: Department of Chemistry, Birjand University, Birjand, Iran.
authors.forename: Somayeh
authors.initials: S
authors.lastname: Khorashahi
authors.affiliation: Department of Civil & Environmental Engineering, Amirkabir University of Technology, Tehran, Iran.
authors.forename: Navid
authors.initials: N
authors.lastname: Hosseini
keywords: 2-Mercaptonicotinic acid; CdSe nanoparticle; Cr(VI) determination; Fluorescence enhancement; Quantum dots
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