Dual-emissive systems showing color-specific photoswitching are promising in bioimaging and super-resolution microscopy. However, their switching efficiency has been limited because a delicate manipulation of all the energy transfer crosstalks in the systems is unfeasible. Here, we report a perfect color-specific photoswitching, which is rationally designed by combining the complete off-to-on fluorescence switching capability of a fluorescent photochromic diarylethene and the frustrated energy transfer to the other fluorescent dye based on the excited-state intramolecular proton transfer (ESIPT) process. Upon alternation of UV and visible light irradiations, the system achieves 100% switching on/off of blue emission from the diarylethene while orange emission from the ESIPT dye is unchanged in the polymer film. By fabricating this system into biocompatible polymer nanoparticles, we demonstrate microscopic imaging of RAW264.7 macrophage cells with reversible blue-color specific fluorescence switching that enables super-resolution imaging with a resolution of 70 nm.

显示特定颜色的光开关的双发射系统在生物成像和超分辨率显微镜中很有前途。然而，由于对系统中所有能量传递串扰的精细操纵是不可行的，因此它们的开关效率受到限制。在这里，我们报告了一种完美的颜色特定的光开关，该光开关是通过将荧光光致变色二芳基乙烯的完全现成的荧光开关功能与基于激发态分子内质子的沮丧的能量转移到另一种荧光染料的结合而合理设计的转移（ESIPT）流程。在紫外线和可见光照射交替时，该系统实现了从二芳基乙烯发出的蓝色发射的100％开/关，而来自ESIPT染料的橙色发射在聚合物膜中未发生变化。