Fluorescent Probes for Detection of Sulfur Dioxide Derivatives

Sulfur dioxide derivatives such as sulfite and bisulfite play dual roles as endogenous signalling molecules and as environmental and food‐processing contaminants. The precise detection of these species is crucial for understanding their physiological functions and mitigating toxicological risks. Fluorescent probes have emerged as powerful tools, offering high sensitivity, rapid response, spatial resolution and minimal invasiveness. Key design strategies include turn-on and ratiometric sensors, often based on intramolecular charge transfer or Förster resonance energy transfer mechanisms, and exploiting reactions such as Michael addition for selectivity. Advances have focused on achieving large Stokes shifts to reduce background interference, submicromolar detection limits for trace analysis, and compatibility with live-cell and real-sample imaging. Organelle-targeted probes enable studies of mitochondrial or lysosomal sulphur dioxide metabolism, while portable test strips and smartphone-compatible formats extend applications to environmental monitoring and food safety. Together, these developments underscore the global significance of fluorescent probes in both fundamental biology and practical regulation of sulfur dioxide derivatives.

Research from Nature Portfolio

Recent studies have introduced a colourimetric and ratiometric probe employing a donor–acceptor FRET pair with an exceptionally large Stokes shift. This sensor achieves a detection limit in the tens of nanomolar range and high specificity against other anions and biothiols. Its nucleophilic addition mechanism enables the fabrication of test strips, and successful ratiometric imaging of exogenous and endogenous bisulfite in living cells demonstrates its quantitative capability.

A complementary development uses a hemicyanine–nitrobenzofurazan conjugate to yield a rapid, dual‐emission ratiometric probe. This design responds within minutes to bisulfite, exhibits excellent selectivity and distinguishes endogenous bisulfite levels in liver cancer cells from those in normal hepatocytes, highlighting its diagnostic potential in oncology research.

Fluorescent Probes for Detection of Sulfur Dioxide Derivatives publication trend

The graph below shows the total number of articles in fluorescent probes for detection of sulfur dioxide derivatives across all publications each year (not limited to Nature Index journals).

Technical terms

Stokes shift: The wavelength difference between the absorption peak and emission peak of a fluorophore, essential for minimising background interference.

Ratiometric detection: A sensing approach that measures the ratio of fluorescence intensities at two wavelengths to enhance quantitative accuracy.

Förster resonance energy transfer (FRET): A non-radiative energy transfer process between a donor and an acceptor fluorophore, used to generate ratiometric signals.

Intramolecular charge transfer (ICT): An electronic transition involving redistribution of electron density within a molecule upon excitation, often exploited for sensing.

Michael addition reaction: A nucleophilic addition of a donor species to an α,β-unsaturated acceptor, frequently employed to confer selectivity for bisulfite or sulfite.

References

1. An effective colorimetric and ratiometric fluorescent probe based FRET with a large Stokes shift for bisulfite. Scientific Reports (2016).
2. A new fluorescent probe for colorimetric and ratiometric detection of sulfur dioxide derivatives in liver cancer cells. Scientific Reports (2017).
3. A near-infrared fluorescent probe for rapid and on-site detection of sulfur dioxide derivative in biological, food and environmental systems. Journal of Hazardous Materials (2023).
4. A mitochondrion-targeted dual-site fluorescent probe for the discriminative detection of SO 3 2− and HSO 3 − in living HepG-2 cells. RSC Advances (2020).
5. A Ratiometric and Colorimetric Hemicyanine Fluorescent Probe for Detection of SO2 Derivatives and Its Applications in Bioimaging. Molecules (2019).