Rare-earth-doped upconversion nanocrystals embedded mesoporous silica nanoparticles for multiple microRNA detection

Simultaneous detection of multiple types of microRNA (miRNA) is of great significance in early cancer diagnosis. In this study, rare-earth-doped CaF 2 upconversion nanocrystals (CaF 2 : RE 3+ , namely Ho 3+ or Tm 3+ and Yb 3+ ) are formed within the mesopores of silica nanoparticles (CaF 2 : RE 3+ @MSN), in an in-situ manner, by capillary effect and thermo-decomposition method. Comparing to current upconversion nanoparticles, the amorphous and mesoporous nature of CaF 2 : RE 3+ @MSN provides abundant active groups and high specific surface area for feasibly immobilizing oligonucleotide probe. The simultaneous and selective detection of multiple miRNAs was achieved based on the photoluminescence spectra of different CaF 2 : RE 3+ @MSN conjugated with DNA probes in the same solution. The results indicated that the proposed approach holds significant potential for multiple miRNA detection and offers an opportunity for cancer early diagnosis.