Aqueous synthesis of core/shell/shell ZnSeS/Cu:ZnS/ZnS quantum dots and their use as a probe for the selective photoluminescent detection of Pb2+ in water
Abstract
Water-dispersible core/shell/shell ZnSeS/Cu:ZnS/ZnS quantum dots (QDs) capped
with 3-mercaptopropionic acid (3-MPA) were successfully prepared via a one-pot method. The
dots are photostable, exhibit a Cu-related photoluminescence (PL) emission located at 500 nm
and a PL quantum yield of 21%. The PL of ZnSeS/Cu:ZnS/ZnS QDs was demonstrated to be
selectively quenched by Pb2+ ions and a method for the rapid and sensitive detection of Pb2+
in real water samples was developed. Under the optimized conditions, the PL intensity of
ZnSeS/Cu:ZnS/ZnS QDs is almost linearly dependent on the Pb2+ concentration in the range of
0.04 to 6 μM and the detection limit is 21 nM in water. Based on PL lifetime and UV-visible
absorption measurements, a dynamic quenching mechanism was demonstrated.
ZnSeS/Cu:ZnS/ZnS QDs were also demonstrated to be efficient probes for the detection of
Pb2+ in real water samples. The developed method is rapid, simple and sensitive and
demonstrates that ZnSeS/Cu:ZnS/ZnS QDs can be used as non-toxic probes to sense Pb2+ ions
in aqueous solution.
| Origin | Files produced by the author(s) |
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