A fast responsive and cell membrane-targetable near-infrared H2S fluorescent probe for drug resistance bioassays in chemotherapy.

A cell membrane-targeted near-infrared fluorescent probe, CMCu-H2S, was fabricated through employing hydrophobic chains and cyclen-Cu2+ as targeting and recognition groups, respectively. NIR fluorescence of CMCu-H2S can significantly increase after reacting with H2S by removing the quenchable Cu2+. This probe exhibited high selectivity and an extremely fast response rate. Cell imaging results demonstrated that there was a close relationship between the overexpression of NFS1 and drug resistance and inhibition of NFS1 was beneficial for improving the efficacy of chemotherapy.