用于生物成像的三线态-三线态湮灭上转换发光纳米胶囊

为解决三线态-三线态湮灭上转换发光材料(TTA-UC)生物应用时固载化困难的问题,通过一步细乳液聚合法合成了以正十六烷为内核,以红光激发的硅酞菁为敏化剂和发光高效的红荧烯为受体,具有优异上转换发光性能的核壳结构纳米胶囊(TTA-UCNP)。TTA-UCNP粒径约为190 nm,均一性及分散性良好。体系引入了抗氧化剂D-柠檬烯和聚异丁烯,有效消除了氧气分子对上转换发光过程的淬灭,保证了上转换发光的稳定性。在动物成像应用中,TTA-UCNP成功实现了活体层次前哨淋巴结高信噪比的成像及长时间示踪。

Triple-Triplet Annihilation Upconversion Nanocapsules for in Vivo Bioimaging

To solve the problem that it is difficult to immobilize triple-triplet annihilation based upconversion (TTAUC) for biological application, water soluble nanocapsules with n-hexadecane core containing a TTA-UC system were synthesized by a one-step miniemulsion polymerization. In the TTA-UC system, silicon phthalocyanine excited by red light source as sensitizer and rubrene with high efficiency as receptor were introduced into n-hexadecane to endow the nanocapsules with upconversion emission. The TTA-UC nanocapsules (TT-UCNP) have a typical coreshell structure with a uniform size of 190 nm. To eliminate the quenching effect of molecular oxygen on upconversion luminescence, D-limonene and polyisobutylene were selected as anti-oxidant, and the TTA-UCNP showed bright upconversion emission. The TTA-UCNP have been successfully applied in in vivo imaging of sentinel lymph node (SLN) with high signal-to-noise ratio and long-term tracing.