Persistent‐luminescence phosphors (PLPs) have a wide variety of applications in the fields of photonics and biophotonics due to their ultralong afterglow lifetime. However, the existing PLPs are charged and recharged with short‐wavelength high‐energy photons or inconvenient and potentially risky X‐ray beams. To date, deep tissue penetrable NIR light has mainly been used for photostimulated afterglow emission, which continues to decay and weaken after each cycle, Herein, a new paradigm of trap energy upconversion‐like near‐infrared (NIR) to near‐infrared light rejuvenateable persistent luminescence in bismuth‐doped calcium stannate phosphors and nanoparticles is reported. In contrast to the existing PLPs and persistent‐luminescence nanoparticles, the materials enable the occurrence of a reversed transition of the carriers from a deep‐level energy trap to a shallow‐level trap upon excitation by low‐energy NIR photons. Thus these new materials can be charged circularly via deep‐tissue penetrable NIR photons, which is unable to be done for existing PLPs, and emit afterglow signals. This conceptual work will lay the foundation to design new categories of NIR‐absorptive–NIR‐emissive PLPs and nanoparticles featuring physically harmless and deep tissue penetrable NIR light renewability and sets the stage for numerous biological applications, which have been limited by current materials.

No abstract

No abstract

Near‐infrared (NIR) persistent luminescent nanoparticles (N‐PLNPs) endow a long‐term in vivo imaging with deep tissue penetration and high signal to noise ratio. However, synthesis route and applicable afterglow center for N‐PLNPs are still limited. Here, we report on a new synthesis by employing chemical precipitation as the central pivot, which is simpler and has controllable and reproducible routes than the existing technique. We also introduce Fe3+ ion as a new member to join the group of afterglow emitters. Although its NIR luminescence is ubiquitous, its NIR afterglow is still almost never reported. In this paper, SrAl12O19: Fe3+ N‐PLNPs display a NIR persistent luminescence from 750 to 1000 nm, which is assigned to 4T1(4G)→6A1(6S) transition of Fe3+. Furthermore, a surface‐amination technique is proposed to improve the stability of SrAl12O19: Fe3+ N‐PLNPs in aqueous solution. After encapsulating the N‐PLNPs with 3‐aminopropyl triethoxysilane (APTES), SrAl12O19: Fe3+ @APTES nanocomposites exhibit a hydrophilic stability beyond 20 days in aqueous solution. The results make them valuable in studying the biological functions of biomolecules and monitoring cellular networks in their native contexts.

In article number 2008722, Yang Li, Jianrong Qiu, Gang Han, and co‐workers propose a new paradigm and milestone study to enable deep‐tissue‐penetrable near‐infrared (NIR) rejuvenateable persistent luminescence. This pioneering work unravels a trap energy upconversion‐like wormhole that can reversely transition the carriers from deep traps to shallow traps.