High-Sensitivity Naphthalene-Based Two-Photon Fluorescent Probe Suitable for Direct Bioimaging of H₂S in Living Cells

Abstract

H2S is the third endogenously generated gaseous signaling compound and has also been known to involve a variety of physiological processes. To better understand its physiological and pathological functions, efficient methods for monitoring of H2S in living systems are desired. Although quite a few one photon fluorescence probes have been reported for H2S, two-photon (TP) probes are more favorable for intracellular imaging. In this work, by employing a donor-π-acceptor-structured naphthalene derivative as the two-photon fluorophore and an azide group as the recognition unit, we reported a new two-photon bioimaging probe 6-(benzo[d]thiazol-2'-yl)-2-azidonaphthalene (NHS1) for H2S with improved sensitivity. The probe shows very low background fluorescence in the absence of H2S. In the presence of H2S, however, a significant enhancement for both one photon and TP excited fluorescence were observed, resulting in a high sensitivity to H2S in aqueous solutions with a detection limit of 20 nM observed, much lower than the previously reported TP probe. The probe also exhibits a wide linear response concentration range (0-5 μM) to H2S with high selectivity. All these features are favorable for direct monitoring of H2S in complex biological samples. It was then applied for direct TP imaging of H2S in living cells with satisfactory sensitivity, demonstrating its value of practical application in biological systems.

A colorimetric and ratiometric fluorescent probe with a large stokes shift for detection of hydrogen sulfide

“…Similar to the previously reported azide-based H 2 S probes, the fluorescence shift and response enhancement of Probe 1 towards H 2 S is most likely ascribed to the H 2 S-induced reduction of the azide group to an amino group [57,58] (Scheme 2). To verify the above proposed reaction mechanism, the HPLC and mass spectra of the reaction product of Probe 1 and NaHS were measured and compared with those of Probe 1 and Compound 2.…”

Recent Progress on the Development of Chemosensors for Gases

“…In a related effort, Zhang developed the two-photon H 2 S fluorescent sensor 104 bearing a naphthalene derivative and an azide group. 121 Sensor 104 displayed a high fluorescence enhancement for both one photon and two photon in response to H 2 S. Moreover, a detection limit of 20 nM was observed, which is much lower than previously reported TP sensors. This two-photon sensor was applied to direct TP imaging of H 2 S in living cells, demonstrating its practical application in the analysis of biological systems.…”

Fluorescent probes for hydrogen sulfide detection and bioimaging

“…Zhang et al synthesized a two-photon fluorescent probe 19 for the detection of H 2 S. 22 This probe employed a naphthalene derivative as the two-photon fluorophore. The detection mechanism of probe 19 was shown in Fig.…”