Core-shell "loading-type" nanomaterials towards: Simultaneous imaging analysis of glutathione and microRNA

A novel type of core-shell "loading-type" nanomaterials, which integrated excellent biocompatibility, high loading capacity, efficient delivery, dual target recognition and response all-in-one, was fabricated for simultaneous imaging analysis of glutathione and microRNAs in living cells. Specifically, the core-shell "loading-type" nanomaterials (termed as MSNs@MnO₂) were formed with mesoporous silica nanoparticles (MSNs) as core and a two-dimensional manganese dioxide nanosheets (MnO₂) as outer layer. Based on the excellent loading capability, the core MSNs was utilized as carriers for signal molecules of rhodamine 6G (R6G). Meanwhile, the shell MnO₂ acted as carriers for nucleic acid compounds, the locker for blocking R6G in the pore of MSNs, and reactant for reacting with redox species. Upon entering the cells, the specific redox reaction between the MnO₂ nanosheets and cellular glutathione (GSH) induced the removal of the locker layer from the MSNs, thereby triggering unlocking, releasing, and recovering the corresponding fluorescence of R6G. While encounter with miRNAs, the molecular beacons (MB) adsorbed on the MnO₂ nanosheets hybridized with target miRNA, which induced the conformational transition of the hairpin molecules, formed new secondary structures, and then recovered the fluorescence signal. Due to the each recovered fluorescence intensity was correlated with the corresponding target molecules, simultaneous detection of dual biomarkers was successfully achieved via the core-shell "loading-type" nanomaterials, which can provide more precise data guidance for diagnosis and disease treatment, and also own promising application in such research area.