Cu2+-modulated cysteamine-capped CdS quantum dots as a turn-on fluorescence sensor for cyanide recognition

Talanta. 2013 Feb 15:105:320-6. doi: 10.1016/j.talanta.2012.10.052. Epub 2012 Oct 22.

Abstract

A new fluorescence sensor for detection of cyanide ions (CN(-)) in aqueous media based on the recovered fluorescence of cysteamine capped CdS quantum dots [Cys-CdS QDs]-Cu(2+) system was proposed. The fluorescence intensity of Cys-CdS QDs was quenched by Cu(2+) due to the binding of Cu(2+) to cysteamine on the surface of the QDs. The degree of fluorescence quenching was proportional to the concentration of Cu(2+). However, in the presence of CN(-), the fluorescence intensity of Cys-CdS QDs was found to be efficiently recovered. Experimental results showed that the pH of the buffer solution and the concentration of Cu(2+) affected the fluorescence intensity upon adding CN(-). Under the optimal condition, the recovered fluorescence intensity was linearly proportional to the increasing CN(-) concentration in the range 2.5-20 μM. The limit of detection and the limit of quantification were found to be 1.13 μM and 3.23 μM, respectively. In addition, among the tested ions, only CN(-) could turn on the fluorescence intensity suggesting that the [Cys-CdS QDs]-Cu(2+) system was a highly selective sensor for CN(-). Moreover, this proposed sensor was demonstrated to detect CN(-) in drinking water with satisfactory results.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cadmium Compounds / chemistry*
  • Copper / chemistry*
  • Cyanides / analysis*
  • Cyanides / chemistry
  • Cysteamine / chemistry*
  • Fluorescence
  • Hydrogen-Ion Concentration
  • Microscopy, Electron, Transmission
  • Quantum Dots*
  • Sulfides / chemistry*

Substances

  • Cadmium Compounds
  • Cyanides
  • Sulfides
  • cadmium sulfide
  • Cysteamine
  • Copper