Effective cancer therapy requires simultaneous in vivo cancer diagnosis and treatment. For this purpose, the development of theranostic nanomedicine with both imaging capabilities and therapeutic functions has attracted increased attention.
Now, Xiaogang Qu and co-workers have reported a smart nanomedicine that combines a pH-activated ratiometric probe with a therapeutic gold nanocage, realizing “sense-act-treat”. By introducing the ratiometric sensor concept, the smart nanodevice can “sense” the tumor through two-state switching of fluorescence, exhibiting green fluorescence at physiological conditions and pH-activated red fluorescence in tumor acidic environments.
This technique could maximize signal from tumors and minimize background signal, improve sensitivity and specificity of in vivo diagnostics. Upon pH-triggered contrasting fluorescence locating the tumor tissue, the nanodevice further provides chemotherapy and hyperthermia for “treating” the tumor by simply controlling the NIR irradiation.