High-Specific Fluorescence Probe for SO₃^2- Detection and Bioimaging

It is well known that sulfite (SO₃^2-) plays an indispensable role in various physiological processes. Abnormal levels of SO₃^2- can trigger a wide variety of diseases involving respiratory, nervous and cardiovascular systems. Hence, it is necessary to find an efficient approach for detection of SO₃^2-. In this study, a pyrene derivative, (E)-4-(3-oxo-3-(pyren-1-yl)prop-1-en-1-yl)phenyl acrylate (PPA), was designed and synthesized for monitoring SO₃^2-. The probe possessed simple synthetic steps, excellent anti-interference ability and specific response to SO₃^2- in the presence of other substances. The reaction between PPA and SO₃^2- was ascribed to Michael addition and the detection mechanism was confirmed by HRMS spectra analysis and FTIR analysis. Additionally, PPA responded linearly to detect SO₃^2- within the rang of 0-100 μM. The limit of detection was calculated as low as 0.17 μM in accordance with the recommendation of IUPAC (CDL =3sb/m). Notably, PPA was further applied in biological imaging in HepG2 cells, which provided a possibility to monitor SO₃^2- in vivo.