A cell surface specific two-photon fluorescent probe for monitoring intercellular transmission of hydrogen sulfide.

Abstract Hydrogen sulfide (H 2 S) is a new endogenously generated gasotransmitter and has implicated in many physiologies and pathologies closely related to its intracellular and intercellular signaling transduction. Although many fluorescent probes have been exploited to track and quantify H 2 S in living systems, none of them could be used for monitoring intercellular transmission of H 2 S. Herein, we developed a cell surface specific H 2 S probe, 4-azido-6-sulfo- N -hexadecyl-1,8-naphthalimide, sodium salt (ASNHN-N 3 ), trying to investigate the behaviors of extracellular release of H 2 S. ASNHN-N 3 is week fluorescent and could react with H 2 S at 37 °C in pH 7.4 buffer solutions to form product ASNHN-NH 2 with strong fluorescence (Φ = 0.22). Using ASNHN-N 3 as H 2 S probe, excellent linear correlation versus the concentration of NaHS was obtained ranging from 0 to 10 μM and the detection limit was 0.75 μM. With the lipid anchor and the hydrophilic sulfonic group introduced into the 1,8-naphthalimide (a skeleton of two-photon fluorescent probe), the amphiphilic probe is located at the surface of living cells which can record H 2 S efflux from the cell diffusing across the plasma membrane in living cells and deep-tissue by using two-photon microscopy. Thus we present a new strategy for further studying the mechanism of signaling molecules in cell communication and signal pathways.