Highly selective and sensitive optosensing of glutathione based on energy level strongly correlated upconversion nanoprobe

To address the problems of short donor-acceptor interaction distance and poor structural stability of the complexes in existing upconversion based luminescence resonance energy transfer (UC-LRET) biosensing technologies. We constructed a LiErF 4 @ZIF-MnO 2 nanoplatform taking advantages of the long-range energy migration characteristics of the energy level strongly correlated LiErF 4 donor and the in situ immobilization technology on the ZIF surface. It significantly improves the solidity of the donor-acceptor structure, breaks the limitation of short LRET distance using the long-range energy migration among Er 3+ ions, realizes the fully utilization of donor LiErF 4 luminescence, and thus effectively improves the LRET efficiency. As a demonstration, this platform exhibited highly sensitive to GSH in solution with a detection limit of 0.14 μM. It presented good photostability, GSH-specific selectivity, and structural robustness under different physiological conditions . We also achieved real-time monitoring of GSH in cells, and effectively distinguished cancer cells from normal cells by the difference in GSH expression levels. The concept of constructing this platform can be of wide interest in the field of biosensing. And the use of long-range energy migration to break the limitations of the short-range action of LRET will make upconversion nanoprobes a more powerful tool for future detection applications.