Herein, a Janus three-dimensional (3D) DNA nanomachine was constructed for the simultaneous and sensitive fluorescence detection and imaging of dual microRNAs (miRNAs) in cancer cells, which could effectively eliminate signal interference in a homogeneous nanoparticle-based 3D DNA nanostructure caused by the proximity of the two different signal probes to achieve accurate co-location in the same position of living cancer cells. In this system, the Janus nanoparticles were synthesized as the carrier for immobilizing two different oligonucleotides on two different functionalized hemispheres of the nanoparticles to form a Janus 3D DNA nanostructure, which could convert trace amounts of miRNA-21 and miRNA-155 targets into massive FAM and Cy5-labeled duplexes to induce two remarkable fluorescence emissions by the catalytic hairpin assembly (CHA) and 3D DNA walker cascade nucleic acid amplification strategy, realizing sensitive detection and imaging of miRNA targets in cancer cells. Impressively, in comparison with current miRNA imaging methods based on nanoparticle assemblies, the proposed strategy could efficiently eliminate “false positive” results obtained in single type miRNA detection and distinctly increase the immobilization concentration of two different signal probes using Janus nanoparticles as the carrier to further enhance fluorescence intensity, resulting in accurate co-location in the same position of living cells. Meanwhile, the proposed fluorescence imaging technology makes it possible to visualize low concentrations of miRNAs with tiny change associated with some cancers, which could significantly improve the accuracy and precision compared to those of the conventional fluorescence in situ hybridization (FISH) approach. Therefore, it could serve as persuasive evidence for supplying accurate information to better understand biological processes and investigate mechanisms of various biomolecules and subcellular organelles, resulting in the further validation of their function in tumor proliferation and differentiation. This strategy provided an innovative approach to design new generations of nanomachines with ultimate applications in bioanalysis and clinical diagnoses.

中文翻译：

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一台Janus 3D DNA纳米机，用于同时敏感的荧光检测和成像癌细胞中的双重microRNA

本文中，构建了Janus三维（3D）DNA纳米机，用于对癌细胞中的双microRNA（miRNA）进行同步，灵敏的荧光检测和成像，从而可以有效地消除由于两种不同信号探针的接近度可在活癌细胞的相同位置实现精确的共位。在该系统中，合成了Janus纳米颗粒作为载体，用于将两种不同的寡核苷酸固定在纳米颗粒的两个不同的功能化半球上，从而形成Janus 3D DNA纳米结构，可以将痕量的miRNA-21和miRNA-155靶标转化为大量FAM和Cy5标记的双链体，通过催化发夹装配（CHA）和3D DNA Walker级联核酸扩增策略诱导两种显着的荧光发射，从而实现灵敏的检测和癌细胞中的miRNA靶标成像。令人印象深刻的是，与当前基于纳米粒子装配体的miRNA成像方法相比，所提出的策略可以有效消除在单型miRNA检测中获得的“假阳性”结果，并以Janus纳米粒子为载体，显着提高两种不同信号探针的固定浓度，从而进一步增强荧光强度，从而在活细胞的相同位置精确定位。与此同时，原位杂交（FISH）方法。因此，它可作为提供准确信息以更好地理解生物学过程并研究各种生物分子和亚细胞器的机制的有说服力的证据，从而进一步证实它们在肿瘤增殖和分化中的功能。该策略提供了创新的方法来设计新一代纳米机器，并将其最终应用于生物分析和临床诊断。