title: Urea-type ligand-modified CdSe quantum dots as a fluorescence "turn-on" sensor for CO3(2-) anions.
abstract: A new fluorescence "turn-on" nanosensor for carbonate determination was reported based on CdSe quantum dots (QDs) modified with thio ligands containing urea groups: N-(5-mercapto-1,3,4-thiadiazol-2-ylcarbamoyl)-2-(o-tolyloxy)acetamide (AASH-CdSe QDs). The AASH-CdSe QDs were prepared through a ligand exchange process and characterized by transmission electron microscopy (TEM), fluorescence spectroscopy, UV-vis spectroscopy and FT-IR spectroscopy. The synthesized AASH-CdSe QDs allowed a selective fluorescence "turn-on" response towards carbonate. Under optimal conditions, the relative fluorescence intensity increases linearly with carbonate concentration in the range 1 x 10(-7)-1 x 10(-4) M with a detection limit of 2.3 x 10(-8) M. A Langmuir-type binding model was highly effective in describing the carbonate concentration dependence of the luminescence intensity of the AASH-CdSe QDs. The possible mechanism was discussed.
authors: Key Laboratory of Pesticide and Chemical Biology (CCNU), Ministry of Education, College of Chemistry, Central China Normal University, Wuhan, 430079, PR China.
authors: Cuiping
authors: C
authors: Han
authors: Zhimin
authors: Z
authors: Cui
authors: Zhilong
authors: Z
authors: Zou
authors: Sabahaiti
authors: Demei
authors: D
authors: Tian
authors: Haibing
authors: H
authors: Li
mesh_terms: D000081:Acetamides / Q000737:chemistry; D000838:Anions / Q000737:chemistry; D019187:Cadmium Compounds / Q000737:chemistry*; D002254:Carbonates / Q000032:analysis*; D005456:Fluorescent Dyes / Q000737:chemistry; D008024:Ligands; D045663:Quantum Dots; D018036:Selenium Compounds / Q000737:chemistry*; D013050:Spectrometry, Fluorescence / Q000379:methods*; D013830:Thiadiazoles / Q000737:chemistry; D014508:Urea / Q000737:chemistry*
chemical_list: D000081:Acetamides; D000838:Anions; D019187:Cadmium Compounds; D002254:Carbonates; D005456:Fluorescent Dyes; D008024:Ligands; D018036:Selenium Compounds; D013830:Thiadiazoles; C058949:1,3,4-thiadiazole; D014508:Urea; C030686:acetamide; C058667:cadmium selenide