title: A simple and sensitive fluorimetric aptasensor for the ultrasensitive detection of arsenic(III) based on cysteamine stabilized CdTe/ZnS quantum dots aggregation.
abstract: A new approach for developing a fluorimetric aptasensor has been described and applied for determination of a highly toxic cation, As(III). In this method an aptamer was used to aggregate cationic cysteamine-stabilized CdTe/ZnS core/shell quantum dots, as a result fluorescence quenching was accrued. In the presence of As(III), the aptamer and As(III) make a complex, which prevents aggregation of the quantum dots. Thus, the fluorescence intensity of the quantum dots was enhanced upon the de-aggregation, which depends on the concentration of As(III). The fluorimetric assay has a very low detection limit of 1.3 pmolL(-1) As(III) with a dynamic range of 1.0 × 10(-11) to 1.0 × 10(-6) molL(-1). The interference effect of a wide variety of cations and anions was investigated, and the obtained results confirm high selectivity of the aptasensor for As(III) detection. The present assay was successfully applied for the determination of As(III) in several water samples.
authors.affiliation: Department of Chemistry, Isfahan University of Technology, Isfahan 84156-83111, Iran. Electronic address: Ensafi@cc.iut.ac.ir.
authors.forename: Ali A
authors.initials: AA
authors.lastname: Ensafi
authors.affiliation: Department of Chemistry, Isfahan University of Technology, Isfahan 84156-83111, Iran.
authors.forename: N
authors.initials: N
authors.lastname: Kazemifard
authors.affiliation: Department of Chemistry, Isfahan University of Technology, Isfahan 84156-83111, Iran.
authors.forename: B
authors.initials: B
authors.lastname: Rezaei
mesh_terms: D001151:Arsenic / Q000032:analysis* / Q000737:chemistry; D019187:Cadmium Compounds / Q000737:chemistry; D003543:Cysteamine / Q000737:chemistry*; D004784:Environmental Monitoring / Q000295:instrumentation*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D053768:Metal Nanoparticles / Q000737:chemistry; D045663:Quantum Dots; D015203:Reproducibility of Results; D018036:Selenium Compounds / Q000737:chemistry; D012680:Sensitivity and Specificity; D013050:Spectrometry, Fluorescence / Q000295:instrumentation*; D013691:Tellurium / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000032:analysis*; D017967:Zinc Compounds / Q000737:chemistry
chemical_list: D019187:Cadmium Compounds; D018036:Selenium Compounds; D014874:Water Pollutants, Chemical; D017967:Zinc Compounds; D003543:Cysteamine; D001151:Arsenic; D013691:Tellurium; C044696:zinc selenide; C028337:cadmium telluride
keywords: Aptasensor; Arsenic (III); Cysteamine-capped CdTe/ZnS core/shell quantum dots; De-aggregation assay