Intratumoral Glutathione Activatable Nanoprobes for Fluorescence and 19F Magnetic Resonance Turn-On Imaging.

Tumor microenvironment turn-on nanoprobes that could specifically detect the occurrence of diseases possess great potential in early diagnosis. Here, a GSH activated nanoprobe was designed for fluorescence and 19F magnetic resonance (MR) dual-modal turn-on imaging of tumors. Specifically, fluorescence AgInS2 quantum dots (QDs for fluorescence imaging) were co-encapsulated with perfluoro-15-crown-5-ether (P19FCE for19F MRI) by amphiphilic polymers and further coated with in situ formed manganese dioxide (MnO2) nanoshells, which served as efficient fluorescence and 19F MR quenchers due to energy transfer and paramagnetic relaxation effects, respectively. The over-expressed GSH in tumors would decompose the MnO2 nanoshells, resulting in remarkable enhancement of both fluorescence and 19F MRI signals of the nanoprobes, accordingly lighting up the tumor site.