Synthesis of cysteamine-coated CdTe quantum dots and its application in mercury (II) detection.

High-quality cysteamine-coated CdTe quantum dots (CA-CdTe QDs) were successfully synthesized in aqueous phase by a facile one-pot method. Through hydroxylamine hydrochloride-promoted kinetic growth strategy, water-soluble CA-CdTe QDs could be obtained conveniently in a conical flask by a stepwise addition of raw materials. The photoluminescence quantum yield (PL QY) of the obtained QDs reached 9.2% at the emission peak of 520   nm. The optical property and the morphology of the QDs were characterized by UV–vis absorption spectra, photoluminescence spectra (PL) and transmission electron microscopy (TEM) respectively. Furthermore, the fluorescence of the resultant QDs was quenched by copper (II) (Cu 2+ ) and mercury (II) (Hg 2+ ) meanwhile. It is worthy of note that to separately detect Hg 2+ , cyanide ion could be used to eliminate the interference of Cu 2+ . Under the optimal conditions, the response was linearly proportional to the logarithm of Hg 2+ concentration over the range of 0.08–3.33   μM with a limit of detection (LOD) of 0.07   μM.