Understanding the biology of gasotransmitters in living cells is of significance but remains challenging due to largely a lack of robust molecular probes. Here, we present the facile design and synthesis of a bioorthogonal Raman probe, 4-azidobenzenethiol (4-ABT), for endogenous hydrogen sulfide (H2S) imaging in single live cells by surface-enhanced Raman scattering (SERS). 4-ABT bears a thiol group and an azido group in the benzene ring, thus affording a bifunction to firmly bind to the gold nanoparticle surface and specifically respond to H2S. Moreover, the 4-ABT-based SERS nanoprobe shows a dose-dependent spectral change in the cellular Raman-silent region upon reacting with H2S, allowing ratiometric quantitative detection and visualization of intracellular H2S status without bio-interference. The ease of fabrication and superior performance of the novel SERS nanoprobe demonstrate its promising application in studies of H2S-related signaling networks.
Keywords: bioorthogonal nanoprobe; hydrogen sulfide; ratiometric visualization; single living cells; surface-enhanced Raman scattering.