H2S-activated fluorescent probe enables dual-channel fluorescence tracking of drug release in tumor cells

Nowadays, the selective release of therapeutic drugs into tumor cells has become an important way of tumor treatment due to the high side effects of chemotherapy drugs. As one of the gas mediators, hydrogen sulfide (H2S) is closely related to cancer. Due to the high content of H2S in tumor cells, it can be used as a signaling molecule that triggers the release of drugs to achieve the selective release of therapeutic drugs. In addition, dual-channel fluorescence imaging technology can be better applied to monitor the drug delivery process and distinguish the state before and after drug release, so as to better track the effect of drug therapy. Based on this, we used NBD amines (NBD-NHR) as the recognition group of H2S and connected the tyrosine kinase inhibitor crizotinib to construct an activated dual-channel fluorescent probe CZ-NBD. After the probe enters the tumor cells, it con-sumes H2S and releases crizotinib, which is highly toxic to the tumor cells. Importantly, the probe displays significant fluorescence changes in different cells, enabling not only the screening of tumor cells, but also tracking and monitoring drug release and tumor cell activity. Therefore, the construction of probe CZ-NBD provides a new strategy for drug release monitoring in tumor cells.