Luminescent NaYF4:Yb,Er@UiO-66 composite based probe for the selective and sensitive detection of Cu2+

In this research, the modified upconversion nanocrystals NaYF 4 :Yb,Er were adopted as the precursors for the synthesis of the NaYF 4 :Yb,Er@UiO-66 composite. The XRD, XPS and TEM characterizations indicated that the composite has good crystallinity and uniform morphology. Under 980 nm excitation, the NaYF 4 :Yb,Er@UiO-66 composite exhibits bright upconversion emission that characterized of Er 3+ : 2 H 11/2 → 4 I 15/2 , 4 S 3/2 → 4 I 15/2 , and 4 F 9/2 → 4 I 15/2 radiative transitions. After modified with BPEI (branched polyethyleneimine), the NaYF 4 :Yb,Er@UiO-66/BPEI fluorescence probe was constructed and was used for the detection of Cu 2+ . The results revealed that the integrated emission intensity of Er 3+ displayed a linear relationship with the concentration of Cu 2+ within the range of 5 to 45 μM with a LOD of 0.9615 μM. This study offered a feasible method for constructing UCNC@UiO-66 composites with regular morphology,which may have a potential application as fluorescent probes for the detection of various metal ions by adjusting the doping luminescent center.