Rational design of pyrrole derivatives with aggregation-induced phosphorescence characteristics for time-resolved and two-photon luminescence imaging

Jianhui Yang,Qian Peng,Yuping Dong,Xinghui Wu,Yahui Zhang,Bin Tong,Zhengxu Cai,Wenbo Dai,Haiyan Xie,Jianbing Shi,Dan Chen,Xin Zhang

doi:10.1038/s41467-021-25174-6

Abstract

Pure organic room-temperature phosphorescent (RTP) materials have been suggested to be promising bioimaging materials due to their good biocompatibility and long emission lifetime. Herein, we report a class of RTP materials. These materials are developed through the simple introduction of an aromatic carbonyl to a tetraphenylpyrrole molecule and also exhibit aggregation-induced emission (AIE) properties. These molecules show non-emission in solution and purely phosphorescent emission in the aggregated state, which are desirable properties for biological imaging. Highly crystalline nanoparticles can be easily fabricated with a long emission lifetime (20 μs), which eliminate background fluorescence interference from cells and tissues. The prepared nanoparticles demonstrate two-photon absorption characteristics and can be excited by near infrared (NIR) light, making them promising materials for deep-tissue optical imaging. This integrated aggregation-induced phosphorescence (AIP) strategy diversifies the existing pool of bioimaging agents to inspire the development of bioprobes in the future.

Highlights

90 s (c)*106 (p/s/cm2/sr)*105 (p/s/cm2/sr) phosphorescence imaging results revealed that the phosphorescence signals from the TPM nanoparticles could be observed at 6 min after the removal of light excitation (Fig. 6c)
The structures were confirmed by 1H and 13C NMR, mass spectrometry, and single-crystal X-ray diffraction (XRD)
Their purities were determined by elemental analysis and high-performance liquid chromatography (HPLC)

Summary

Introduction

90 s (c)*106 (p/s/cm2/sr)*105 (p/s/cm2/sr) phosphorescence imaging results revealed that the phosphorescence signals from the TPM nanoparticles could be observed at 6 min after the removal of light excitation (Fig. 6c). Since aromatic carbonyls can act as rotors to consume excited energy, the obtained compounds preserve the AIE character while simultaneously generating phosphorescent emission. Both the emission intensities and lifetimes of TPM/TPM-Cl increase with decreasing temperature from 290 to 80 K

Results

Conclusion