Kai Wen,Xingdong Yang,Cuiling Zhang,Huiying Wei,Guizheng Zou,Ye Zhu
Diffusion-mediated homogeneous electrochemical assay has attracted substantial attention owing to its simplicity, rapid response, and high recognition efficiency, however, lack of inherent connection between signal reporter and electrode surface restricts the improvement of detection sensitivity and further limits its potential applications. Herein, a facile electrochemical strategy is proposed through integrating the advantages of traditional heterogeneous assay and homogenous assay. In this strategy, a small amount of target DNA can trigger the release of assist DNA from the electrode surface. Then, the assist DNA can induce the homogeneous amplification reaction, which in turn promotes the amplification on the electrode surface by generating numerous target DNA analogues, thereby realizing positive feedback signal amplification. As a result, ultrasensitive electrochemical detection of nucleic acids was achieved in the dynamic range from 5 aM to 5 fM with a detection limit down to 1.2 aM. There is about 2.5 orders of magnitude improvement in sensitivity compared with the control strategy without homogeneous amplification. Moreover, the proposed strategy was demonstrated with high selectivity, reproducibility, and capability of detecting nucleic acids in serum samples, displaying its promising potential in the development of ultrasensitive electrochemical biosensing platform for disease diagnosis applications.
Qianlong Wang,Lancong Liu,Xiaoyi Chen,Tiantian Wang,Hua Zhou,Hui Huang,Linsen Qing,Pei Luo
Urine is the most appropriate body fluid for analysis because it is easily and less-invasively obtained than blood; thus, urinary miRNAs can better represent the local stage of the disease and might grow up to be a new class of noninvasive biomarkers of postmyocardial infarction (MI). Monofunctionalized Au nanoparticles (AuNPs) with only one selective DNA at a specific location are more promising in nanotechnology. This study developed a urinary miRNA ultratrace detection strategy based on single-target DNA-functionalized AuNPs for the noninvasive prognosis of post-MI. The AuNPs were designed with only single-stranded biotinylated DNA complementary to the target miRNA through a ratio-optimized stoichiometric method for the first time. Combined with the duplex specific nuclease-assisted target recycling amplification, the single-target DNA-functionalized AuNPs for the first time were used in inductively coupled plasma–mass spectrometry for the determination of urinary miRNA with high sensitivity. After optimizing the reaction conditions, a linear detection range between 1 fM and 10 pM for miR-155 and a detection limit of 0.47 fM were obtained. Finally, the target miR-155 in urine samples collected from MI rats was quantified and the level of miR-155 in MI groups was 30 times higher than in the control groups. The results suggest that urinary miR-155 could be a novel biomarker for the noninvasive diagnosis of MI.
Wang Dan,Chen Ling,Li Chengbi,Long Quanxin,Yang Qing,Huang Ailong,Tang Hua
Background Currently, there are no curative drugs for hepatitis B virus (HBV). Complete elimination of HBV covalently closed circular DNA (cccDNA) is key to the complete cure of hepatitis B virus infection. The CRISPR/Cas9 system can directly destroy HBV cccDNA. However, a CRISPR/Cas9 delivery system with low immunogenicity and high efficiency has not yet been established. Moreover, effective implementation of precise remote spatiotemporal operations in CRISPR/Cas9 is a major limitation.Results In this work, we designed NIR-responsive biomimetic nanoparticles (UCNPs-Cas9@CM), which could effectively deliver Cas9 RNP to achieve effective genome editing for HBV therapy. HBsAg, HBeAg, HBV pgRNA and HBV DNA along with cccDNA in HBV-infected cells were found to be inhibited. These findings were confirmed in HBV-Tg mice, which did not exhibit significant cytotoxicity and minimal off-target DNA damage.Conclusion sThe UCNPs-based biomimetic nanoplatforms achieved the inhibition of HBV replication via CRISPR therapy and it is a potential system for efficient treatment of human HBV diseases.Graphical Abstract
危险品化学品经营许可证（带存储）