Key Laboratory of Luminescence Analysis and Molecular Sensing (Southwest University), Ministry of Education, College of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, P. R. China.
Anal Chem. 2024 Jul 2;96(26):10738-10747. doi: 10.1021/acs.analchem.4c01833. Epub 2024 Jun 19.
Herein, CsPbBr perovskite quantum dots (CPB PQDs)@poly(methyl methacrylate) (PMMA) (CPB@PMMA) nanospheres were used as energy donors with high Förster resonance energy transfer (FRET) efficiency and exceptional biocompatibility for ultrasensitive dynamic imaging of tiny amounts of microRNAs in living cells. Impressively, compared with traditional homogeneous single QDs as energy donors, CPB@PMMA obtained by encapsulating numerous CPB PQDs into PMMA as energy donors could not only significantly increase the efficiency of FRET via improving the local concentration of CPB PQDs but also distinctly avoid the problem of cytotoxicity caused by divulged heavy metal ions entering living cells. Most importantly, in the presence of target miRNA-21, DNA dendrimer-like nanostructures labeled with 6-carboxy-tetramethylrhodamine (TAMRA) were generated by the exposed tether interhybridization of the Y-shape structure, which could wrap around the surface of CPB@PMMA nanospheres to remarkably bridge the distance of FRET and increase the opportunity for effective energy transfer, resulting in excellent precision and accuracy for ultrasensitive and dynamic imaging of miRNAs. As proof of concept, the proposed strategy exhibited ultrahigh sensitivity with a detection limit of 45.3 aM and distinctly distinguished drug-irritative miRNA concentration abnormalities with living cells. Hence, the proposed enzyme-free CPB@PMMA biosensor provides convincing evidence for supplying accurate information, which could be expected to be a powerful tool for bioanalysis, diagnosis, and prognosis of human diseases.
在此，我们使用 CsPbBr 钙钛矿量子点（CPB PQDs）@聚甲基丙烯酸甲酯（PMMA）（CPB@PMMA）纳米球作为能量供体，其具有高Förster 共振能量转移（FRET）效率和卓越的生物相容性，可用于在活细胞中对微量 microRNAs 进行超灵敏的动态成像。令人印象深刻的是，与传统的均相单量子点作为能量供体相比，通过将大量 CPB PQDs 封装到 PMMA 中作为能量供体而获得的 CPB@PMMA 不仅可以通过提高 CPB PQDs 的局部浓度显著提高 FRET 的效率，而且还可以明显避免由于泄露的重金属离子进入活细胞而引起的细胞毒性问题。最重要的是，在存在靶 miRNA-21 的情况下，带有 6-羧基四甲基罗丹明（TAMRA）标记的 DNA 树状大分子状纳米结构通过 Y 形结构的暴露连接杂交而产生，其可以缠绕在 CPB@PMMA 纳米球的表面上，从而显著缩短 FRET 的距离并增加有效能量转移的机会，从而实现对 miRNA 的超灵敏和动态成像的出色精度和准确性。作为概念验证，所提出的策略具有超高的灵敏度，检测限低至 45.3 aM，并且可以明显区分具有活细胞的药物刺激性 miRNA 浓度异常。因此，所提出的无酶 CPB@PMMA 生物传感器为提供准确信息提供了令人信服的证据，有望成为生物分析、诊断和人类疾病预后的有力工具。
