Fluorescent Probes for Hydrogen Sulfide Detection in Biological Systems

Fluorescent probes have emerged as indispensable tools for the selective and sensitive detection of hydrogen sulfide (H₂S), a pivotal gaseous signalling molecule implicated in vascular homeostasis, neuromodulation and cellular redox regulation. By coupling specific chemical reactions—such as reduction of azide groups, thiolysis of electron-deficient moieties or coordination to metal centres—with fluorogenic scaffolds, these probes enable real-time, non-invasive imaging of H₂S in complex biological environments. Advances in probe design now encompass near-infrared (NIR) and two-photon excitation modalities for deep-tissue penetration, organelle targeting for subcellular resolution, and dual-reactable constructs that distinguish H₂S from abundant biothiols. The variety of fluorophores—rhodamine, naphthalimide, resorufin or metal-organic frameworks—has enhanced photostability and tunable emission wavelengths. Practical applications span live-cell imaging, zebrafish embryo studies and mouse models, with growing potential for disease diagnosis, therapeutic monitoring and elucidation of H₂S biology across physiological and pathological contexts.

Research from Nature Portfolio

Recent studies have introduced a near-infrared turn-on probe capable of visualising both exogenous and endogenous H₂S with high sensitivity and low cytotoxicity in living cells and murine models. An endoplasmic reticulum-targeted two-photon fluorescent probe has been developed to achieve selective detection of H₂S within the ER microenvironment, demonstrating a large fluorescence enhancement, deep-tissue imaging in living tissues and applicability in zebrafish. Furthermore, a dual-reactable probe that integrates thiolysis and redox mechanisms has enhanced selectivity and fluorescence turn-on fold, offering robust detection of H₂S in aqueous buffer and living cells while minimising interference from other reactive species.

Fluorescent Probes for Hydrogen Sulfide Detection in Biological Systems publication trend

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

Technical terms

Fluorescent probe: A molecule engineered to produce a measurable fluorescence signal upon interaction with a specific analyte.

Turn-on fluorescence: An increase in fluorescence intensity triggered by a chemical reaction or binding event with the target.

Near-infrared (NIR): Wavelength region (650–900 nm) enabling reduced background and deeper tissue penetration.

Two-photon excitation: A nonlinear optical process using simultaneous absorption of two photons to excite a fluorophore, allowing high-resolution imaging in thick tissues.

Stokes shift: The difference between excitation and emission wavelengths of a fluorophore, affecting signal discrimination.

Thiolysis: Cleavage of a chemical bond by reaction with a thiol (–SH), often used for H₂S sensing via thiol nucleophilicity.

Redox reaction: A chemical process involving electron transfer that can be exploited to convert non-fluorescent moieties into fluorescent products.

References

1. A highly selective and sensitive near-infrared fluorescent probe for imaging of hydrogen sulphide in living cells and mice. Scientific Reports (2016).
2. A turn-on endoplasmic reticulum-targeted two-photon fluorescent probe for hydrogen sulfide and bio-imaging applications in living cells, tissues, and zebrafish. Scientific Reports (2017).
3. A Redox-Nucleophilic Dual-Reactable Probe for Highly Selective and Sensitive Detection of H2S: Synthesis, Spectra and Bioimaging. Scientific Reports (2016).
4. Hydrogen sulfide detection and zebrafish imaging by a designed sensitive and selective fluorescent probe based on resorufin. Spectrochimica Acta Part A Molecular and Biomolecular Spectroscopy (2021).