Synthesis of New AIEE-Active Chalcones for Imaging of Mitochondria in Living Cells and Zebrafish In Vivo.

Huiqing Luo,Feng He,Na Li,Huaqiao Wang,Liyan Liu

doi:10.3390/ijms22168949

Abstract

Fluorophores with aggregation-induced emission enhancement (AIEE) properties have attracted increasing interest in recent years. On the basis of our previous research, we successfully designed and synthesized eleven chalcones. Through an optical performance experiment, we confirmed that compounds 1–6 had obvious AIEE properties. As these AIEE molecules had excellent fluorescence properties and a large Stokes shift, we studied their application in living cell imaging, and the results showed that these compounds had low cytotoxicity and good biocompatibility at the experimental concentrations. More importantly, they could specifically label mitochondria. Subsequently, we selected zebrafish as experimental animals to explore the possibilities of these compounds in animal imaging. The fluorescence imaging of zebrafish showed that these AIEE molecules can enter the embryo and can be targeted to aggregate in the digestive tract, which provides a strong foundation for their practical application in the field of biological imaging. Compared with traditional fluorophores, these AIEE molecules have the advantages of possessing a small molecular weight and high flexibility. Therefore, they have excellent application prospects in the field of biological imaging. In addition, the findings of this study have very positive practical significance for the discovery of more AIEE molecules.

Highlights

Organic fluorescent dyes have been generally applied to biological imaging, fluorescent probes, pathological detection, and other fields on account of their strong fluorescence emission [1,2,3,4]
We successfully designed and synthesized chalcone derivatives 1–11 based on our previous research of aggregation-induced emission enhancement (AIEE) molecules
We determined that the main reason for the AIEE phenomenon was the restriction of intramolecular rotation (RIR)

Summary

Introduction

Organic fluorescent dyes have been generally applied to biological imaging, fluorescent probes, pathological detection, and other fields on account of their strong fluorescence emission [1,2,3,4]. Traditional organic fluorescent dyes often show an aggregation-caused quenching (ACQ) phenomenon, which severely limits their practical application. ACQ molecules emit strong fluorescence in low-concentration solutions, but show fluorescence quench in high concentrations or solid state [5]. Tang’s research group first discovered a compound with an aggregation-induced emission (AIE) phenomenon called 1-methyl-1,2,3,4,5-pentaphenylsilole in 2001 [6]. Fluorescence molecules with this property show weak emission in solution but show a dramatically enhanced emission in high concentrations and solid state, which is contrary to the ACQ phenomenon [7].

Methods

Results

Conclusion