Ultra-stable and highly-bright CsPbBr3 perovskite/silica nanocomposites for miRNA detection based on digital single-nanoparticle counting

• Published in: Talanta (Oxford) 2024-06, Vol.273, p.125903-125903, Article 125903
• Main Authors: Zhong, Jiajun, Ge, Minghao, Gu, Tongxu, Wang, Tong, Liu, Zhizhou, Bai, Pengli
• Format: Article
• Language: English
• Subjects: CsPbBr3; Mesoporous silica; miRNA detection; PbBr(OH); Single-nanoparticle counting
• ISSN: 0039-9140; 1873-3573
• DOI: 10.1016/j.talanta.2024.125903

Single-nanoparticle counting (SNPC) based on fluorescent tag (FT) stands out for its capacity to achieve amplification-free and sensitive detection of biomarkers. The stability and luminescence of FT are important to the sensitivity and reliability of SPNC. In this work, we developed novel perovskite/silica nanocomposites by in-situ nanoconfined growth of CsPbBr3 nanocrystals inside mesoporous structure of silica nanoparticles. PbBr(OH) was formed in an alkaline-assisted reaction triggered by water on the surface of CsPbBr3 nanocrystals. The as-obtained nanocomposites, featuring dual protection from silica matrix and PbBr(OH), exhibited high absolute photoluminescence quantum yield (PLQY) of 86.5% and demonstrated outstanding PL stability confronting with water, heat, ultrasound and UV-irradiation, which is desired by SNPC-based biosensor. Thereafter, these nanocomposites were used to construct an operationally friendly SNPC assay for the amplification-free quantification of cancer-associated miRNA. Quantitative detection of miRNA could be accomplished by directly counting the number of nanocomposites using a flow cytometer in this assay. This strategy did not ask for multiple washing steps and demonstrated specific and sensitive detection of miRNA 21, which exhibited a dynamic range of 1–1000 pM and limit of detection of 79 amol. The employment of highly stable perovskite/silica nanocomposites improved the test reliability and stability of SNPC, revealing the vast potential of perovskites in biosensing. [Display omitted] •Dual protection from silica and PbBr(OH) ensured the excellent PL stability of CsPbBr3 perovskite/silica nanocomposites.•Perovskite nanocrystals were used to construct a single-nanoparticle counting (SNPC) based assay for cancer diagnosis.•The excellent PL properties of CsPbBr3 perovskite/silica nanocomposites improved the reliability and stability of SNPC assay.•The amplification-free assay without multiple washing steps achieved the specific and sensitive quantification of miRNA 21.