As an important endogenous signaling molecule, SO₂ plays a key role in many physiological processes. However, excessive intake of SO₂ and its derivatives lead to serious health complications of various diseases. In order to study the role of SO₂ and its derivatives in the biological environment, it is of great significance to develop new and effective monitoring methods. Here, a new red emission fluorescent probe (TNPI) based on pyrazoline and hemicyanine dyes for the high selective detection of SO₂ derivatives was developed. The probe TNPI showed some advantages such as long emission wavelength (640 nm), obvious color and fluorescence changes after reaction with SO₂ derivatives, high selectivity and sensitivity toward SO₂ derivatives (detection limit = 80 nM), and large fluorescence emission shift (160 nm) and signal ratio change (from 0.45–445, about 989 times). Intriguingly, the probe was successfully exploited for the fluorescence imaging of SO₂ derivatives in the mitochondria of living cells with low cytotoxicity.

作为重要的内源性信号分子，SO ₂在许多生理过程中起着关键作用。然而，过量摄入SO ₂及其衍生物会导致各种疾病严重的健康并发症。为了研究SO ₂及其衍生物在生物环境中的作用，开发新型有效的监测方法具有重要意义。在这里，开发了一种基于吡唑啉和半菁染料的新型红色发射荧光探针（TNPI），用于SO ₂衍生物的高选择性检测。TNPI探针具有一些优点，例如发射波长长（640 nm），与SO ₂反应后颜色和荧光变化明显。衍生物，对SO ₂衍生物的高选择性和敏感性（检测限= 80 nM），大的荧光发射位移（160 nm）和信号比变化（从0.45–445，约为989倍）。有趣的是，该探针已成功地用于具有低细胞毒性的活细胞线粒体中SO ₂衍生物的荧光成像。