title: A selective determination of copper ions in water samples based on the fluorescence quenching of thiol-capped CdTe quantum dots.
abstract: CdTe quantum dots (QDs) capped with different stabilizers, i.e. thioglycolic acid (TGA), 3-mercaptopropionic acid (MPA) and glutathione (GSH) were investigated as fluorescent probes for the determination of Cu(2+). The stabilizer was shown to play an important role in both the sensitivity and selectivity for the determination of Cu(2+). TGA-capped CdTe QDs showed the highest sensitivity, followed by the MPA and GSH-capped CdTe QDs, respectively. The TGA- and MPA-capped CdTe QDs were not selective for Cu(2+) that was affected by Ag(+). The GSH-capped CdTe QDs were insensitive to Ag(+) and were used to determine Cu(2+) in water samples. Under optimal conditions, quenching of the fluorescence intensity (F0/F) increased linearly with the concentration of Cu(2+) over a range of 0.10-4.0 µg/mL and the detection limit was 0.06 µg/mL. The developed method was successfully applied to the determination of Cu(2+) in water samples. Good recoveries of 93-104%, with a relative standard deviation of < 6% demonstrated that the developed simple method was accurate and reliable. The quenching mechanisms were also described.
authors.affiliation: Trace Analysis and Biosensor Research Center, Prince of Songkla University, Hat Yai, Songkhla, 90112, Thailand.|Center of Excellence for Innovation in Chemistry, Department of Chemistry, Faculty of Science, Prince of Songkla University, Hat Yai, Songkhla, 90112, Thailand.
authors.forename: Piyaluk
authors.initials: P
authors.lastname: Nurerk
authors.affiliation: Trace Analysis and Biosensor Research Center, Prince of Songkla University, Hat Yai, Songkhla, 90112, Thailand.|Center of Excellence for Innovation in Chemistry, Department of Chemistry, Faculty of Science, Prince of Songkla University, Hat Yai, Songkhla, 90112, Thailand.
authors.forename: Proespichaya
authors.initials: P
authors.lastname: Kanatharana
authors.affiliation: Trace Analysis and Biosensor Research Center, Prince of Songkla University, Hat Yai, Songkhla, 90112, Thailand.|Center of Excellence for Innovation in Chemistry, Department of Chemistry, Faculty of Science, Prince of Songkla University, Hat Yai, Songkhla, 90112, Thailand.
authors.forename: Opas
authors.initials: O
authors.lastname: Bunkoed
mesh_terms: D019187:Cadmium Compounds / Q000737:chemistry*; D003300:Copper / Q000032:analysis*; D005453:Fluorescence; D005456:Fluorescent Dyes / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D007477:Ions / Q000032:analysis; D015394:Molecular Structure; D045663:Quantum Dots; D013438:Sulfhydryl Compounds / Q000737:chemistry*; D013691:Tellurium / Q000737:chemistry*; D014867:Water / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D019187:Cadmium Compounds; D005456:Fluorescent Dyes; D007477:Ions; D013438:Sulfhydryl Compounds; D014874:Water Pollutants, Chemical; D014867:Water; D003300:Copper; D013691:Tellurium; C028337:cadmium telluride
keywords: copper ion; quantum dots; quenching