Abstract
The synthesis of nanostructures with asymmetric configurations in terms of both geometries and compositions has attracted extensive interest in recent years. In this work, we describe a protocol for the synthesis of high quality heterodimers made of upconversion nanoparticles (UCNPs) and porphyrinic nanoscale metal-organic frameworks (nMOF). Tuning the surface chemistry of UCNPs plays a key role for the formation of heterodimers in a controllable fashion. The hydrophobic UCNPs are firstly coated with polyvinylpyrrolidone to convert them into hydrophilic ones and to facilitate subsequent nucleation and growth of nMOFs on their surface. Then, UCNP-MOF heterodimers (UCMOFs) are synthesized through the anisotropic growth of nMOFs on UCNPs in the presence of optimal precursors in dimethyl formamide solution. To demonstrate the versatility of the approach, core-multishell structured UCNPs are also prepared to serve as seeds for the growth of UCNP-MOF heterodimers. Such UCNP-MOF heterodimers hold a great promise for various applications, such as NIR-induced photodynamic therapy, drug delivery, photocatalysis, and solar cell.
