Core-satellite upconversion nanocrystals@metal organic frameworks composite for the detection of hydrogen peroxide

Luminescent metal organic frameworks (MOFs) based composites have potential applications for sensitive and selective detection of various substances like heavy metal cations, glucose, biogas molecules and antibiotics. In this research, the UCNCs@MOFs composites were synthesized by combing the rare earth ions doped NaYF 4 nanocrystals with ZIF-8 and UiO-66-NH2 MOFs, respectively, both of which exhibit core-satellite structures with good crystallinity, high pore volume and large specific surface area, as well as excellent upconversion luminescence performance under 980   nm excitation. The differences in the detail morphology and formation mechanism of the composites were compared based on TEM, XPS, FTIR, Zeta potential, N 2 adsorption and desorption isotherm characterizations. After loading with NiS x nanoparticles, the real-time to initial total emission intensity ratio (I/I 0 ) of Er 3+ in NaYF 4 :Yb,Er@ZIF-8/NiS x and NaYF 4 :Yb,Er@UiO-66-NH 2 /NiS x probes, and the emission intensity ratio of Tm 3+ peaked at 476 and 802   nm (I 476nm /I 802nm ) in NaYF 4 :Yb,Tm@UiO-66-NH 2 /NiS x probe can be applied to the sensitive and selective detection of H 2 O 2 , in which the last one shows the superior LOD. This research presented a universal method for the synthesis of various UCNCs@MOFs composites with tunable upconversion emission and microstructure by combing MOFs with desirable UCNCs, which may promote their applications in sensing, detection, and display.