Cancer cell recognition by a Cys-reactive turn-on significant enhanced fluorescent emission targeting biotin receptors

Cancer is a leading cause of death worldwide. The discrimination of cancer cells from normal cells is of importance for early diagnosis. Designing and synthesizing fluorescent probes that precisely target cancer cells can greatly aid treatment efforts. Biotin can target over-expressed receptors on the surface of cancer cells. In addition, the abundant free biothiols in cells play important roles in many physiological and pathological processes. We therefore developed a fluorescein derivative probe possessing an acryloyl group as a reaction site for detecting biothiol and biotin as a cancer cell-targeting agent. Thus, cancer cells over-expressing the biotin receptor are labeled via a fluorescence signal significant enhancement from the reaction product of the probe and Cys, enabling the probe (Ac) to distinguish cells via imaging. The probe is successfully applied to distinguish among four cell types, Hela, B16, RAW264.7 and NIH-3T3.