AIE-based dual-ratiometric chemosensor for detection of sulfur dioxide derivatives and viscosity and its application in food samples and biological imaging

Abstract

Background

SO₂ is an important gas molecular messenger that participates in many physiological activities and helps maintaining the redox homeostasis in biological system. Especially, SO₂ can effectively regulate oxidative stress and improve mitochondrial morphology. Abnormal mitochondrial viscosity can lead to a variety of diseases. Therefore, it is of great importance to detect SO₂ derivatives and cell viscosity in biological systems.

Results

Here, two mitochondria-targeted and dual-ratiometric chemosensors (TPE-1 and TPE-2) based on tetraphenylethene were constructed, which could be used to simultaneously detect SO₂ derivatives and cell viscosity. Notably, TPE-2 as the preferable due to its superior discernibility to HSO₃⁻ than that of TPE-1. Moreover, TPE-2 featured rapid response, high sensitivity, excellent selectivity, and low cytotoxicity under physiological conditions which means that TPE-2 is more suitable for practical application than TPE-1. The response mechanism of TPE-2 for HSO₃⁻ was confirmed by the theoretical calculation and mass spectral analysis. Meanwhile, TPE-2 showed enhanced fluorescence intensity the increased viscosity environment due to it was subjected to structural rotation. In addition, the practical application for detecting HSO₃⁻ in real water samples was successfully carried out with good recovery, the test strips loaded TPE-2 was prepared and the detection of HSO₃⁻ in food samples was realized by a convenient smartphone analysis. Importantly, TPE-2 had good mitochondrial targeting ability and had successfully imaged HSO₃⁻ and viscosity in HeLa cells and zebrafish.

Significance

This study provides an effective and potential tool for detecting HSO₃⁻ and viscosity in mitochondria and in vivo, the rational design strategy in this work holds potential to inspire the development of more powerful dual-response chemosensor for other biological factors.