ACS Sensors
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2024
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IF 8.2
Lin He,Yan Zhou,Min Zhang,Mingjian Chen,Yuchen Wu,Lanlin Qi,Lamei Liu,Bin Zhang,Xiaohai Yang,Xiaoxiao He,Kemin Wang
Detection of slight pH changes in skin interstitial fluid (ISF) is crucial yet challenging for studying pathological processes and understanding personal health conditions. In this work, we construct an i-motif DNA based fluorescent ratiometric microneedle sensing patch (IFR-pH MN patch) strategy that enables minimally invasive, high-resolution, and sensitive transdermal monitoring of small pH variations in ISF. The IFR-pH MN patch with advanced integration of both ISF sampling and pH sensing was fabricated from the cross-linking of gelatin methacryloyl and methacrylated hyaluronic acid, wrapping with pH-sensitive hairpin-containing i-motif DNA based fluorescent ratiometric probes in the matrix. Because it is mechanically robust for skin penetration and has high swelling ability, the IFR-pH MN patch could be quickly extracted as sufficient liquid from agarose gel (∼56.4 μL in 10 min). Benefiting from conformation changes of the hairpin-containing i-motif DNA under pH variation and ratiometric fluorescence signal readout, the IFR-pH MN patch could quantitate pH over a small range between pH 6.2 and 6.9 with an accuracy of 0.2 pH units in the mimic skin model. Furthermore, in vivo testing on wound and tumor mouse models indicated the ability of the biocompatible IFR-pH MN patch to penetrate the skin for obtaining transdermal pH values, demonstrating the potential applications in monitoring and intervention of pathological states.
研究领域:
生物医学工程
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分子生物学
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传感技术
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DOI
PubMed
高影响因子
ANALYTICAL CHEMISTRY
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2020
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IF 6.785
Lu Shi,Feifei Cao,Limin Zhang,Yang Tian
The development of switches responding to specific pH changes was particularly useful in wide application fields. Owing to flexible switches simulated by pH, i-motif DNAs are widely used as a pH sensor. But its character of structure transition strongly dependent on acidic pH severely hampers the application of i-motif DNA in physiological media. Herein, we report the stable i-motif structure formed at a physiological pH triggered by spatial confinement of silica nanochannels. Three classic DNA chains containing 21-mer i-motif domain base-pairs and a single-stranded multiply (T)n spacer, 5′-COOH-(T)n-CCCTAACCCTAACCCTAACCC-3′, were employed to evaluate the enhanced stability of i-motif structure. Compared to their free states in a dilute solution, the transition pH of all i-motif DNAs decorated in nanochannels remarkably shifts toward a neutral pH. Moreover, the transition midpoint can be tuned sensitively over the physiologically relevant pH range through slightly varying the length of T base spacer. Density functional theory (DFT) calculations validate that the increased proton density in a nanochannel triggers the formation of an i-motif structure under a neutral pH. Finally, this i-motif DNA based nanochannels electrode was successfully employed to monitor pH in brain microdialysates followed by cerebral ischemia. The present approach is not limited by fundamental investigation for DNA conformation but may extend toward the manipulation of i-motif based structures for artificial molecular machines and signaling systems.
研究领域:
生物化学
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分子生物学
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医学检测
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PubMed
高影响因子
NUCLEIC ACIDS RESEARCH
·
2025
·Vol. 53
·期 12
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IF 13.1
Luo Tengshuo,Guan Ziyue,Liu Yunlong,Zhou Jun,Mergny Jean-Louis,Cheng Mingpan
A molecular beacon (MB) is an oligonucleotide probe with a stem-loop structure designed to fluoresce upon hybridization with a specific target nucleic acid. Herein, we introduce a novel i-motif DNA-based molecular beacon (iMB) designed for nucleic acid detection. DNA chemical sequencing showed that the iMB can be selectively opened when its target is present, thanks to the formation of a duplex between this target and the iMB recognition loop. Phase diagrams were introduced to analyze the binding properties between the iMB and its target, and to optimize the detection conditions with different combinations of pH and temperature. Benefiting from the environment-sensitive stability and special structural feature inherent to the i-motif, this iMB exhibits a controllable sensitivity and specificity through choosing appropriate temperature/pH combination and recognition loop position in the i-motif probe. Leveraging the duplex-specific nuclease (DSN) resistance of the i-motif, we significantly enhanced the sensitivity by more than four orders of magnitude through the implementation of a DSN-assisted amplification strategy. Finally, miRNAs in cell lines and patient plasma were detected by the iMBs, as validated via quantitative reverse transcription polymerase chain reaction (RT-qPCR). This research successfully broadens the structural repertoire of MB stems to include a pH- and temperature-responsive i-motif stem.
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高影响因子
ACS Sensors
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2020
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IF 7.333
Dandan Zhao,Haoran Tang,Hao Wang,Cheng Yang,Yongxin Li
The nanopore-based technique is a useful tool for single-molecule sensing and characterization. In this work, we have developed a new DNA-functionalized gold-modified nanopore, and analytes can induce the conformational switch of i-motif DNA formed on the inner surface of the nanopore. i-Motif DNA structure can be formed in the presence of silver ions (Ag+), which will result in the change in surface charge and structure of the nanopore tip and ion current rectification (ICR) ratio. The i-motif DNA structure on nanopore surface will be destroyed after the addition of glutathione (GSH) due to the strong interaction of Ag–S bond, which results in the recovery of surface charge, steric hindrance, and ICR ratio. This analyte-triggered conformational switch of i-motif DNA can help us deeply understand the DNA technology inside single nanopore and will benefit the possible applications in an ultrasensitive detection and biological/chemical analysis.
研究领域:
纳米技术
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生物物理学
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分子生物学
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分析化学
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PubMed
高影响因子
MOLECULAR PHARMACEUTICS
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2020
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IF 4.321
Dandan Miao,Yanyan Yu,Yong Chen,Yin Liu,Gaoxing Su
Stimuli-responsive DNA-based nanostructures have emerged as promising vehicles for intelligent drug delivery. In this study, i-motif DNA-conjugated gold nanostars (GNSs) were fabricated in a facile manner as stimuli-responsive drug delivery systems (denoted as A-GNS/DNA/DOX) for the treatment of cancer via combined chemo-photothermal therapy. The i-motif DNA is sensitive to the environmental pH and can switch from a single-stranded structure to a C-tetrad (i-motif) structure as the environmental pH decreases from neutral (∼7.4) to acidic (<6.0). The loaded drug can then be released along with the conformational changes. To enhance cellular uptake and improve cancer cell selectivity, the aptamer AS1411, which recognizes nucleolins, was employed as a targeting moiety. The A-GNS/DNA/DOX nanocomposites were found to be highly capable of photothermal conversion and exhibited photostability under near-infrared (NIR) irradiation, and the pH and NIR irradiation effectively triggered the drug-release behaviors. In addition, the A-GNS/DNA/DOX nanocomposites exhibited good biocompatibility. The targeting recognition enabled the A-GNS/DNA/DOX to exhibit higher cellular uptake and therapeutic efficiency than the GNS/DNA/DOX. Notably, under NIR irradiation, a synergistic effect between chemotherapy and photothermal therapy can be achieved with the proposed delivery system, which exhibits much higher therapeutic efficiency both in monolayer cancer cells and tumor spheroids as compared with a single therapeutic method. This study highlights the potential of GNS/DNA nanoassemblies for intelligent anticancer drug delivery and combined cancer therapy.
研究领域:
纳米技术
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癌症研究
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药物递送系统
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生物医学工程
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高影响因子
TALANTA
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2016
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IF 4.035
Bei Hua Kang,Zhong Feng Gao,Na Li,Yan Shi,Nian Bing Li,Hong Qun Luo
Silver ions have been widely applied to many fields and have harmful effects on environments and human health. Herein, a label-free optical sensor for Ag + detection is constructed based on thiazole orange (TO) as a fluorescent probe for the recognition of i-motif DNA structure change at neutral pH. Ag + can fold a C-rich single stranded DNA sequence into i-motif DNA structure at neutral pH and that folding is reversible by chelation with cysteine (Cys). The DNA folding process can be indicated by the fluorescence change of TO, which is non-fluorescent in free molecule state and emits strong fluorescence after the incorporation with i-motif DNA. Thus, a rapid, sensitive, and selective method for the detection of Ag + and Cys is developed with a detection limit of 17 and 280 nM, respectively. It is worth noting that the mechanism underlying the increase of the fluorescence of thiazole orange in the presence of i-motif structure is explained. Moreover, a fluorescent DNA logic gate is successfully designed based on the Ag + /Cys-mediated reversible fluorescence changes. The proposed detection strategy is label-free and economical. In addition, this system shows a great promise for i-motif/TO complex to analyze Ag + in the real samples.
研究领域:
分析化学
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生物化学
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分子生物学
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环境科学
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PubMed
高影响因子
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