Stimulus-responsive strategy based on MnO₂ nanosheet-modified mesoporous silica nanoprobes for accurate multiple...

Fluorescence detection of multiple mRNAs has attracted great attention for disease diagnosis. In this work, a stimulus-responsive strategy for highly sensitive and accurate multiple mRNAs detection was proposed. This stimulus-responsive detection system was prepared by mesoporous silica nanoparticles (MSN), manganese dioxide (MnO₂) nanosheets, and DNA probes. DNA probes were loaded into the pores of MSN, which were closed with MnO₂ nanosheets. In the presence of glutathione (GSH) and target mRNAs, MnO₂ nanosheets were degraded by GSH, resulting in the release of DNA probes. These DNA probes hybridized to the corresponding target mRNA, thereby changing the fluorescence intensity of fluorophores of DNA probes, which could achieve the quantification of target mRNA. This system could simultaneously detect survivin mRNA and Thymidine kinase 1 mRNA at low background levels with relative limits of detection of 0.9 nM and 0.7 nM, respectively. Moreover, this assay has been successfully applied to detect multiple mRNAs with adequate anti-interference ability in the biological sample.