Cu and Fe Sensor Based on CdTe QD@ZIF-8 Composites.

TGA capped CdTe QDs have been encapsulated in miroporous ZIF-8, with no obvious deterioration of their photoluminescence property. The resulted CdTe QD@ZIF-8 composites show a higher luminescent stability in various buffer solution. The material has successfully been used as a luminescent indicator for the detection of Cu and Fe ions. The luminescence of CdTe QD@ZIF-8 composite quenches only in the presence of Cu or Fe ions. The linear ranges of detection have been estimated as 1~50 uM for Cu ions and 1~60 uM for Fe ions, respectively. A "competing transmission" mechanism has been proposed to explain the selectivity of the sensor to detecting Cu and Fe ions. Luminescent quenching can only occurred when the bonding power of QD surface surpasses the adsorptivity of the outside ZIF-8 to the metal ions.