Luminescent CdTe quantum dots and nanorods as metal ion probes

Water-soluble luminescent thiol-capped CdTe QDs and nanorods have been synthesized and used to investigate the effect on their photoluminescence (PL) responses to divalent metal ions, such as zinc, calcium, magnesium, manganese, nickel, and cobalt ions. The change trends of PL were nearly similar for both CdTe QDs and nanorods. The zinc ions enhanced the photoluminescence, while the manganese, nickel, and cobalt ions quenched the PL. The effect on the PL response of CdTe QDs to divalent metal ions could be described by Langmuir-type binding model or Stern-Volmer-type equation. The CdTe nanorods were more sensitive to metal cations than QDs, and their enhancement mechanisms are different. CdTe QDs and nanorods maybe used as selective ion probes and developed as fluorescence sensors.