Multifunctional Silica-Based Optical Nanoparticles with Aqueous-Phase Multicolor Room-Temperature Phosphorescence and Structural Color
Mingda Shan, Kongchen Wang, Kun Yang, Man Wang, Jing Du, Jiaqiang Wang, Jiayi Liang, Lihuan Tong, Su Chen, Zhongxiang Qiu, Yishan Yin, Chunlin Du, Huihui Cui, Yanwen Qi, Wenbo Wu, Ben Zhong Tang, Zhen LiAbstract
Developing organic−inorganic hybrid nanomaterials generating multiple optical signals remains challenging due to inherent design complexities. Herein, we present organic-SiO2 nanohybrids exhibiting size-dependent room-temperature phosphorescence (RTP) and structural color. By employing a covalent anchoring strategy, silanized organic phosphors are incorporated into the SiO2 matrix, protecting triplet excitons and enabling multicolor aqueous RTP emission with a maximum lifetime of 314.81 ms. Notably, as particle size increases, organic-SiO2 RTP nanohybrids exhibit an approximately 2-fold enhancement in RTP lifetime and generate a red-shifted structural color signal through self-assembly. The long-lived luminescence and excellent biocompatibility of NPA@SiO2 (H-120) enable in vivo afterglow imaging without additional covering treatments. Within 0.5 h after tail vein injection at an ultralow chromophore dose (0.25 mg kg−1), tumor sites in mice are precisely localized via efficient cellular uptake, representing superior imaging performance. Furthermore, the unique multiplexed optical features of organic-SiO2 nanohybrids provide significant advantages for anti-counterfeiting labeling and multi-level encryption applications.