NQO1 and viscosity tandemly responsive NIR fluorescent probe for tumor imaging and monitoring tumor apoptosis

As a common process of programmed cell death, apoptosis plays crucial roles in the occurrence and therapy of tumor. Identifying tumor cells and monitoring tumor cells apoptosis is of great significance in tumor diagnosis and therapy. Herein, a NAD(P)H: quinine oxidoreductase (NQO1) and viscosity tandemly responsive near-infrared fluorescent probe HCy-Q is designed. Firstly, HCy-Q is specifically activated by over-expressed NQO1 to identify NQO1-positive tumor cells. Secondly, the product of HCy-Q hydrolyzed by NQO1 is sensitive to viscosity and capable of detecting mitochondrial viscosity changes. During the doxorubicin-induced apoptosis process of A549 cells, a significant increase in mitochondrial viscosity is observed by using HCy-Q. The novel detection model of NQO1 and viscosity tandemly response makes HCy-Q with great potential for tumor imaging and monitoring tumor apoptosis in vitro and vivo.