Nanoscale Rhodium(I) Based Metal-Organic Framework Demonstrating Intense NIR-II Luminescence for Bioimaging.

Abstract

Although luminescent metal-organic frameworks (MOFs) have been widely reported, rare examples were found to emit in the second near-infrared (NIR-II, 1000-1700 nm) window. In this work, two nanoscale rhodium(I)-based MOFs (<b>Rh-1@SDS</b> and <b>Rh-1@DSPE-PEG</b>) have been controllably constructed in the aqueous dispersions of sodium dodecyl sulfate (SDS) and 1,2-distearoyl-<i>sn</i>-glycero-3-phosphoethanolamine-<i>N</i>-methoxy-poly(ethylene glycol) (DSPE-PEG), wherein micelle- and vesicle-like aggregates form, respectively, with high colloidal stability. The vesicular dispersion of <b>Rh-1@DSPE-PEG</b> exhibits intense NIR-II luminescence at 1125 (1245, shoulder) nm. Consequently, this nanoMOF was used as an NIR-II luminescence probe, indicative of high-resolution systemic and local vascular imaging, where the postoperative recovery process of flap transplantation was clearly visualized. Meanwhile, it also demonstrates superior tumor targeting in the NIR-II window. To the best of our knowledge, this research represents the first example of nanoMOFs having intense NIR-II luminescence and excellent imaging capabilities.