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 520nm. 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 0.08-3.33μM with a limit of detection (LOD) of 0.07μM.