TALANTA
·
2021
·
IF 6.057
Ting Huang,Guixun Chen,Birong Liu,Zizhong Yang,Yuanwei Huang,Baoping Xie,Min-Min Li,Jin-Xiang Chen,Jun Chen,Zong Dai
Sensitive, specific and rapid methods for detecting microRNAs (miRNAs) play critical roles in disease diagnosis and therapy. Enzyme-free amplification techniques based on DNAzyme assembly have recently been developed for the highly specific miRNA analysis. However, traditional DNAzyme-based assembly (free DNAzyme) amplifiers is mainly dependent on the target-induced split DNAzyme fragments to assemble into activated DNAzyme structures, which have made a compromise between the sensitivity and specificity due to the random diffusion of dissociative probes in a bulk solution with poor kinetics. Herein, based on a rationally designed DNA probe , we developed an intramolecular DNAzyme assembly (intra-DNAzyme) method to overcome these challenges. The miR-373 is used as model analyte for our current proof-of-concept experiments. Compared with the free-DNAzyme method, our method showed significantly improved analytical performance in terms of dynamic range, assay sensitivity and speed. This method can detect miR-373 specifically with a detection limit as low as 4.3 fM, which is about 83.7 times lower than the previous free-DNAzyme method. This intra-DNAzyme strategy would be of great value in both basic research and clinical diagnosis.
研究领域:
分子生物学
·
生物技术
·
纳米技术
·
诊断学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
TALANTA
·
2020
·
IF 5.339
Wenyue Zhang,Wenhui Hao,Xuetao Liu,Xiru Sun,Jingli Yan,Yucong Wang
A visualized assay for miRNAs detection has been developed in this work. The presented method is based on a combination of enzyme-free amplification cascades of catalyzed hairpin assembly (CHA) and hybridization chain reaction (HCR) and fluorescence quenching of dual-emission ratiometric fluorescent probes (RF probes). MiRNAs can efficiently initiate enzyme-free amplification reactions (CHA and HCR) and produce the long nicked dsDNAs with a lot of glucose oxidases (GOD) on the surface of dynabeads bridged by the GOD-labeled hairpin DNA probes . Hydrogen peroxide (H 2 O 2 ) is generated by oxidation of glucose catalyzed by GOD, which can quench the outer green fluorescence without affecting the internal red fluorescence of RF probes. Therefore, increased miRNA amount can result in change of the two fluorescence intensity ratios of RF probes with continuous color changes from green to red under a UV lamp, which can be easily recognized by naked eye. The proposed assay exhibits high sensitivity toward let-7a with dynamic range from 10 −13 M to 10 −8 M, and which is applied successfully to detecting let-7a in the small RNA samples.
研究领域:
分子生物学
·
生物化学
·
医学诊断
✓ 已验证
DOI
PubMed
高影响因子
Journal of Materials Chemistry C
·
2022
·Vol. 10
·期 48
·18258-18263
·
IF 8.067
Li Ping Cao,Yao Wang,Yan Bai,Yong Jian Jiang,Chun Mei Li,Yuan Fang Li,Cheng Zhi Huang,Shu Jun Zhen
Owing to their simple and convenient synthesis, the application of metal–organic gels (MOGs) in fluorescence detection has been increasingly studied. However, most relevant studies are based on the fluorescence changes of MOGs themselves caused by the direct interaction between the target and MOG, resulting in limited universality and insufficient sensitivity and other shortcomings. Thus, we combined a Cu-based metal–organic gel (Cu-MOG) with an entropy-driven circuit (EDC), as an isothermal enzyme-free amplification technique, to detect miR-155 as a proof-of-principle target. The substrate for the EDC was designed as a three-strand duplex (TD) containing an output strand (OS) which was modified with 6-carboxyfluorescein (FAM). In the presence of the target, namely miR-155, the EDC was triggered and OS was released, making the OS transition from the hybrid state to the free state. The fluorescence of the FAM modified free OS strand was then quenched owing to the intramolecular photo-induced electron transfer (PET) of the new ground state complex formed between the OS and MOG with a quenching constant of 1.48 mL μg−1, which is much higher than that (0.08 mL μg−1) of the hybrid state OS. This method provided a dynamic detection range of 1 nM to 5 nM with a detection limit of 0.23 nM for miR-155, demonstrating that the Cu-MOG coupled EDC has promising applications in bioassays, and opens up a new application field of MOGs in EDC development.
研究领域:
分析化学
·
生物传感器
·
纳米技术
·
分子生物学
✓ 已验证
产品关联
DOI
高影响因子
MICROCHEMICAL JOURNAL
·
2022
·
IF 5.304
Wenjing Wang,Fei Zhai,Fupei Xu,Min Jia
Novel enzyme-free amplified dual-terminal labeled split aptamer (SPA) probes were developed to achieve one-step rapid and sensitive detection of bisphenol A (BPA). By rational split, the original aptamer was divided into two segments named SPA-a and SPA-b to achieve target-driven self-assembly and form BPA/SPA complex. To achieve enzyme-free signal amplification and improved sensitivity, SPA probes were dual-terminal labeled with 6-carboxyfluorescein (FAM) fluorophores and black hole quencher 2 (BHQ 2 ). Two dual-terminal labeled SPA probes were induced to assemble a ternary complex with BPA to produce fluorescence resonance energy transfer effect, generating the decreased fluorescence intensity. The detection limit of dual-terminal labeled SPA probes was 0.89 ng/mL, which was 24-fold lower than that of single-terminal modification. Meanwhile, these SPA probes showed a rapid response to BPA, which could be completed in 5 min for one-step detection without complex cleaning and separation progress. The recovery rates in real samples were 94.17% to 107.28%. In brief, the dual-terminal labeled SPA probes showed substantial potential for onsite detection of BPA.
研究领域:
分析化学
·
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）