3D Long-Range Triplet Migration in a Water-Stable Metal-Organic Framework for Upconversion-Based Ultralow-Power in Vivo Imaging. Academic Article uri icon


  • Triplet-triplet annihilation upconversion (TTA-UC) has gained increasing attention because it allows for harvesting of low-energy photons in the solar spectrum with high efficiency in relevant applications including solar cells and bioimaging. However, the utilization of conventional TTA-UC systems for low-power bioapplications is significantly hampered by their general incompatibility and low efficiency in aqueous media. Herein we report a metal-organic framework (MOF) as a biocompatible nanoplatform for TTA-UC to realize low-power in vivo imaging. Our MOF consists of a porphyrinic sensitizer in an anthracene-based Zr-MOF as a TTA-UC platform. In particular, closely aligned chromophores in the MOF facilitate a long-range 3D triplet diffusion of 1.6 m allowing efficient energy migration in water. The tunable ratio between sensitizer and annihilator by our synthetic method also allows an optimization of the system for maximized TTA-UC efficiency in water at a very low excitation power density. Consequently, the low-power imaging of lymph node in a live mouse was successfully demonstrated with an excellent signal-to-noise ratio (SNR > 30 at 5 mW cm-2).

published proceedings

  • J Am Chem Soc

altmetric score

  • 0.25

author list (cited authors)

  • Park, J., Xu, M., Li, F., & Zhou, H.

citation count

  • 114

complete list of authors

  • Park, Jihye||Xu, Ming||Li, Fuyou||Zhou, Hong-Cai

publication date

  • April 2018