Near-Infrared Emissive Lanthanide Metal–Organic Frameworks for Targeted Biological Imaging and pH-Controlled Chemotherapy

Near-infrared window II (NIR-II, 1000–1700 nm) imaging displays the advantages in deep-tissue high-contrast imaging in vivo on the strength of the high temporal–spatial resolution and deeper penetration. However, the clinical utility of NIR-II imaging agents is limited by their single function. Herein, for the first time, we report the design of a multifunctional drug delivery system (DDS) assembly, CQ/Nd-MOF@HA nanohybrids, with NIR-II fluorescence (1067 nm), large Stokes shifts, and ultrahigh quantum yield, which combined targeted NIR-II luminescence bioimaging and pH-controlled drug delivery. The nanoscale metal–organic framework (MOF) as a highly promising multifunctional DDS for targeted NIR-II bioimaging and chemotherapy in vitro and in vivo lays the foundation of the MOF-based DDS for further clinical diagnosis and treatment.