CHEMICAL PHYSICS
·
2021
·
IF 2.348
Zenan Zhao,Simin Cao,Haoyang Li,Dong Li,Yanping He,Xin Wang,Jinquan Chen,Sanjun Zhang,Jianhua Xu,Jay R. Knutson
Thiazole orange (TO), an asymmetric cyanine dye , has been widely used in biomolecular detection and imaging of DNA/ RNA in gels, due to its unique fluorogenic behavior: fluorescence of free dye in aqueous solution is very weak, but emission can be significantly enhanced in nucleic-acid-bound dye. Herein we describe the ultrafast excited-state dynamics of free TO in aqueous solution by exploiting both a femtosecond upconversion spectrophotofluorometer and a picosecond time-correlated single-photon counting (TCSPC) apparatus. For the first time, the fluorescence lifetime of TO monomer in water was found to be ∼1 ps, mixed with concurrent solvent relaxation (which was confirmed by the experimental results of TO in DMSO). Even at moderate TO concentration, this lifetime has an amplitude (a measure of molecular fraction) that significantly dominates other lifetimes, and this is the origin of weak steady state fluorescence of free TO in water. We also found a novel slower decay component around 34 ps. Interestingly and in addition, the lifetime component on the 30–40 ps timescale was also found in TO-γ-Cyclodextrin (CD) complexes. The fraction of this component increased with the addition of γ-CD. Cyclodextrin has been reported to promote the aggregation of TO. Thus, although a very coincidental match of this time constant by one for a torsional process within the cavity can not be ruled out, we ascribe the shared 30–40 ps component to the lifetime of a highly quenched TO dimer experiencing intra-and inter-molecular rearrangement.
研究领域:
生物物理学
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光化学
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分子生物学
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DOI
PubMed
高影响因子
ANALYTICAL LETTERS
·
2022
·
IF 2.267
Hongjing Sun,Zheng Liu,Zhihong Li,Xinyue Ma,Zixuan Duan,Chunyan Sun
A simple and label-free fluorescent sensor based upon a specific DNAzyme (8–17 DNAzyme) and thiazole orange (TO) for monitoring Pb2+ in water samples was described. The 8–17 DNAzyme was formed by an enzyme strand (17E) and a partially complementary substrate strand (17DS). Thiazole orange, the DNA intercalator, was nonfluorescent in aqueous solution while it intercalates into the 8–17 DNAzyme with a duplex structure resulting in strong fluorescence. In the presence of Pb2+, the 17E was activated and cleaved the 17DS into two at the ribonucleoside adenosine (rA) position, leading to the disruption of the duplex structure. This Pb2+-induced conformational change led to the quenching of the fluorescence of thiazole orange, thus forming the basis for the label-free biosensor. Under the optimized conditions, the developed protocol exhibited sensitive determination of Pb2+ with a detection limit of 0.73 nM and a linear range from 10 to 150 nM. The label-free fluorescent approach exhibited excellent selectivity, strong selectivity, and satisfactory analysis of a drinking water standard reference material and spiked river and tap water samples. Taking the advantage of the structure-switching 8–17 DNAzyme and the fluorescent intercalator of nucleic acids, this label-free sensor provides a new approach for routine screening of heavy metals based upon the DNAzyme.
研究领域:
分析化学
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环境科学
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生物化学
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DOI
高影响因子
DYES AND PIGMENTS
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2018
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IF 3.767
Wei Long,Yu-Jing Lu,Kun Zhang,Xuan-He Huang,Jin-Qiang Hou,Sen-Yuan Cai,Ying Li,Xian Du,Leonard G. Luyt,Wing-Leung Wong,Cheuk-Fai Chow
New fluorescent dyes derivatized on a classical thiazole orange framework are able to show unexpectedly strong interaction signal and unusual binding selectivity with different structures of nucleic acid , particularly when bound with double-stranded DNA or G-quadruplex DNA. The present study reveals that these small binding ligands simply bearing an additional amino side group on its parent molecule of thiazole orange have almost no background fluorescence in solution. Conversely, they are able to produce an extremely strong yellow emission signal upon interaction with targeting nucleic acids in live cells. The induced fluorescence intensity was approximately 10–15 times stronger than that of thiazole orange. The dyes are therefore excellent fluorescent stains for bio-sensing and bio-imaging applications. It is particularly suitable for fluorescence microscopy experiments requiring very low working concentration (0.25 μM or less) targeting nucleic acids. This was demonstrated using pu27 G-quadruplex DNA, which has a low limit of detection (LOD = 3–4 nM) while thiazole orange was much higher (LOD = 48.7 nM) under the same conditions. In addition, it was found that structural modification on the quinolinium scaffold of thiazole orange was less effective than modification on the benzothiazole moiety. The findings of the present study provide important information for structural advancement of small molecules based on the widely used thiazole orange skeleton, resulting in analogues that are able to achieve higher sensitivity and selectivity for targeting at a specific class of nucleic acids. Computational docking studies were also conducted to illustrate the interaction behaviors of the dyes with different DNA structures.
研究领域:
生物化学
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分子生物学
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分析化学
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DOI
高影响因子
CHEMISTRY-A EUROPEAN JOURNAL
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2017
·Vol. 23
·期 42
·10092-10099
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IF 5.317
Jing Zhang,Qing Tang,Zhong-Zheng Gao,Sheng-Chao Qiu,Ying Huang,Zhu Tao
Graphical Uniquely responsive : The interaction of thiazole orange (TO) with twisted cucurbit[14]uril ( t Q[14]) was investigated, and formation of a stable fluorescent t Q[14]/TO complex was observed. The t Q[14]/TO complex exhibited unique fluorescence responses to Hg 2+ , Ba 2+ , and Pb 2+ cations in different aqueous media (see figure). Thus, a fluorescent sensor for three heavy-metal ions was developed. A water-soluble fluorescent sensor based on the interaction of twisted cucurbit[14]uril ( t Q[14]) and thiazole orange (TO) in aqueous solution was developed. Formation of the t Q[14]/TO complex gives rise to stronger fluorescence in both neutral and acidic aqueous solutions compared with that of free TO. Further experiments on the interaction of the t Q[14]/TO complex with metal ions revealed that, from a series of nineteen selected common metal ions, 1) only Hg 2+ can lead to fluorescence enhancement and then quenching of the t Q[14]/TO (2:1) complex in neutral aqueous solution; 2) only Ba 2+ can induce fluorescence quenching of the t Q[14]/TO (2:1) complex in aqueous HCl solution (pH 2); furthermore, the t Q[14]/TO/Ba 2+ systems exhibit reversible changes in fluorescent intensity on successively adding SO 4 2− and Ba 2+ ; and 3) only Ba 2+ or Pb 2+ can induce fluorescence quenching of the t Q[14]/TO (15:1) complex in aqueous HCl solution (pH 2). Thus, the t Q[14]/TO complex can act as a supramolecular fluorescence-based sensor for the determination of Hg 2+ , Ba 2+ , and Pb 2+ ions.
研究领域:
化学
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分析化学
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超分子化学
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DOI
PubMed
高影响因子
ANALYST
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2014
·Vol. 139
·期 24
·6387-6392
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IF 3.906
Chunyan Gao,Henan Li,Yuanjian Liu,Wei Wei,Yuanjian Zhang,Songqin Liu
Strategies to detect the methylation of site specific DNA and assay of M.SssI methyltransferase (M.SssI MTase) activity are important in determining human cancers due to aberrant methylation linked to cancer initiation and progression. Herein, we report a label-free fluorescence detection method for DNA methylation and MTase activity based on restriction endonuclease HpaII and exonuclease III (Exo III). A label-free probe DNA was designed, which hybridized with target DNA (one 32-mer DNA from the exon 8 promoter region of the Homo sapiens p53 gene) to form double stranded DNA (dsDNA). Upon the cleavage action of HpaII and degradation reaction of Exo III, dsDNA changed to single stranded DNA (ssDNA) and the fluorescence intensity of thiazole orange (TO) is weak. After the resulting dsDNA was methylated by M.SssI MTase, the action of HpaII and Exo III was prevented, then TO intercalates into the dsDNA and emits strong fluorescence. This method can determine DNA methylation at the site of CpG and distinguish a one-base mismatched target sequence. The fluorescence intensity has a linear relationship with M.SssI MTase activities in the range of 1–10 U mL−1 with a detection limit of 0.16 U mL−1 in terms of 3 times deviation of the blank sample. The methylation of DNA by a hydroxyl radical triggered by DMSO and CH3CHO was also measured. These results show that the proposed method can specifically and selectively detect DNA methylation and M.SssI MTase activity. Human serum has no obvious effects on the assay performance, indicating that the method has great potential for further application in complex samples.
研究领域:
生物化学
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分子生物学
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遗传学
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癌症研究
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DOI
PubMed
高影响因子
SENSORS AND ACTUATORS B-CHEMICAL
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2023
·
IF 8.4
Huimin Hao,Li Peng,Bin Yang,Guo-Jiang Mao,Jian Zhu,Shuyan Lou
Colorimetric biosensors are suitable for point-of-care assays due to the advantages of simple operation, fast analysis and direct visualization. Here a novel oxidase mimic of thioflavin T via light-activating was first discovered. Various chromogenic substrates can be efficiently oxidized via light-activated singlet oxygen ( 1 O 2 ). In particular, thioflavin T often binds to some unique conformations in bio-macromolecules (e.g., DNA G-quadruplex) with good specificity. This is valuable to develop versatile colorimetric biosensors with signal-switching functionality for direct visualizing of analytes. Using various recognition elements (molecular beacons, aptamers), we can realize the efficient assay of five different analytes, including mechlorethamine , DNA, K + , adenosine monophosphate, and amyloid fibril . Therefore light-activated oxidase mimic of thioflavin T can serve as a desirable tool to assay various analytes of pharmaceutical, food or environmental interest.
研究领域:
生物化学
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分析化学
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DOI
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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DOI
PubMed
高影响因子
BIOORGANIC CHEMISTRY
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2021
·
IF 5.275
Wangqing Bian,Zhenxing Pan,Yakun Wang,Wei Long,Zefeng Chen,Niping Chen,Yaoxun Zeng,Jiongpeng Yuan,Xujie Liu,Yu-Jing Lu,Yan He,Kun Zhang
Organic small molecules with near-infrared (NIR) absorption hold great promise as the phototheranostic agents for clinical translation by virtue of their inherent merits such as well-defined chemical structure, high purity and good reproducibility. Probes that happen to be based on cyanine dyes exhibit strong NIR-absorbing and efficient photothermal conversion, representing a new class of photothermal agents (PAs) for photothermal therapy (PTT), and taking into account the heat susceptibility of Mitochondria (Mito), we designed and prepared a mitochondria-targeted organic small molecule (Mito-BWQ) based on thiazole orange maternal unit that can effectively kill tumor cells through the hyperpyrexia generated in the lesions under exogenous laser irradiation. The Confocal laser scanning microscope was employed to determine the preferential targeting of Mito-BWQ to the mitochondria of MCF-7 cells and U87 cells. When subjected to 600 nm laser radiation, Mito-BWQ produced an increase in temperature in test systems and this increase was dependent on both the laser power and probe concentration. In vitro tests, cytotoxicity was observed when cells were incubated with Mito-BWQ and exposed to laser irradiation. The PTT in vivo also showed that Mito-BWQ performed remarkably in tumor inhibition. This study thus provides a vital starting point for the creation of thiazole orange-based PTT formulations and promotes further advances in the field of PAs-based anticancer research and therapy.
研究领域:
肿瘤学
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药学
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生物医学工程
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化学
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DOI
PubMed
高影响因子
CHEMBIOCHEM
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2021
·Vol. 22
·期 11
·1948-1954
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IF 3.164
Yaoyao Hou,Jianjun Hou,Xixia Liu
Graphical Two very different DNA aptamers have been reported for dopamine, one derived from an RNA aptamer (named Apt1) and other obtained via direct aptamer selection (named Apt2). In this study, we used four homogeneous binding assays to compare these two DNA dopamine aptamers. Apt1 does not appear to be able to bind dopamine specifically, while Apt2 showed specific binding and could be used for developing related biosensors. Dopamine is an essential neurotransmitter and its detection is important for bioanalytical chemistry. Two very different DNA aptamers have been reported for dopamine, one derived from an RNA aptamer (named Apt1) and other obtained via direct aptamer selection (named Apt2). In this study, we used four homogeneous binding assays to compare these two DNA dopamine aptamers. Thiazole orange (TO) fluorescence assay indicated that the Apt2 specifically bound with dopamine with a K d of 2.37 μM, which was consistent with that from the isothermal titration calorimetry (ITC) assay. However, Apt1 had much less TO fluorescence change and also no signal from ITC. By labeling the two ends of the two aptamers by a fluorophore and a quencher, the aptamer beacons showed binding of dopamine only for Apt2. Finally, the label-free AuNP-based colorimetric assay showed no difference between these two aptamer sequences, and even non-binding random DNA showed the same response, indicating that AuNPs were not a good probe for detecting dopamine. According to the data, Apt1 does not appear to be able to bind dopamine specifically, while Apt2 showed specific binding and could be used for developing related biosensors.
研究领域:
分析化学
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生物化学
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生物传感器开发
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DOI
PubMed
高影响因子
SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
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2021
·
IF 4.098
Lingling Zhang,Mengwen Yi,Shilong Zhong,Jing Liu,Xiangjun Liu,Tao Bing,Nan Zhang,Yongbiao Wei,Dihua Shangguan
Viscosity of cell microenvironment plays a significant role in maintaining the normal life activities of cells. Particularly, the abnormal viscosity in mitochondria is closely associated with lots of diseases and cellular dysfunctions. Herein, we developed a group of p-aminostyryl thiazole orange derivatives with different amino side chains. These probes showed good fluorescence response to viscosity with twisted intramolecular charge transfer mechanism, among them, the probes with diethylamino ( TOB ), dibutylamino ( TOC ) and pyrrolidin ( TOE ) side chains showed better response to the viscosity with 78-fold, 55-fold, and 88-fold fluorescence enhancement in 95% glycerol solution respectively. TOB , TOC , and TOE could enter live cells and mainly located in mitochondria. Treatment HeLa cells with nystatin, lipopolysaccharide or oleic acid caused significant fluorescence enhancement of these probes, suggesting the good potential for monitoring the variation of mitochondrial viscosity, as well as for investigating the related physiological process of inflammation and lipid metabolism.
研究领域:
细胞生物学
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生物化学
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分子生物学
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药理学
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产品关联
DOI
PubMed
高影响因子
MICROCHEMICAL JOURNAL
·
2024
·
IF 4.9
Jidong Tang,Ling Wang,Wenjin Ma,Ping Fu,Yanlin Zhang,Xiaoqiong Li,Xiaoqi Tao
The application of the fluorescence resonance energy transfer (FRET) strategy in the detection of ochratoxin A (OTA) is restricted by factors such as the photobleaching of fluorescent dyes, the autofluorescence of ochratoxin A (OTA), and the necessity for excitation by an external light source. The chemiluminescence resonance energy transfer (CRET) technique provides a more effective solution to this issue. In this paper, we developed a novel CRET aptasensor, based on gold nanoparticle (AuNP)-mediated CRET and Nb.BbvCI-powered DNA walker signal amplification. In the AuNPs/Capture-DNA/HRP probe, horseradish peroxidase (HRP) approached the AuNP surface, resulting in CRET. AuNPs quenched the chemiluminescence generated by HRP-catalyzed luminol. The presence of OTA induced the separation of the Walk-DNA from the aptamer and the formation of a double strand with Capture-DNA. This activated Nb.BbvCI to cleave Capture-DNA, releasing HRP and Walk-DNA. The Walk-DNA acted as a DNA walker, moving toward the adjacent Capture-DNA and initiating the next cleavage by Nb.BbvCI. Ultimately, a significant amount of HRP was released from the AuNP surface, weakening the CRET effect while generating a strong chemiluminescent signal. The CRET aptasensor had a detection limit of 2.75 nM with a linear range of 5–40 nM and was applied to detect OTA in glutinous rice.
研究领域:
食品科学
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生物传感
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分析化学
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产品关联
DOI
高影响因子
MICROCHEMICAL JOURNAL
·
2024
·
IF 4.9
Ze Chen,Zuyao Fu,Xiaoyu Du,Jing Xie,Zhaoyang Ding
Simple fluorescence aptasensors were established for malachite green (MG) and leucomalachite green (LMG) detection using G-quadruplex dyes thioflavin T (ThT) and thiazole orange (TO), respectively. ThT and TO, initially non-fluorescent in aqueous solution, exhibited fluorescence upon binding to target-specific aptamers, resulting in the stabilization of G-quadruplex structures. The specific binding between G-quadruplex and MG could induce conformational changes, which caused a pronounced quenching of fluorescence emitted by the intercalator, providing a possibility for detection. The developed assays demonstrated a good linear relationship in the range of 0–1000 μg L -1 for MG and 0–250 μg L -1 for LMG, with low limits of detection of 5.4 × 10 -3 μg L -1 and 0.1 μg L -1 respectively. More importantly, satisfactory detection results in water and fish samples were obtained. Noteworthy was that the uncomplicated fluorescent aptasensors operated effectively without the need for any modifications. The experimental process was facile and realized in homogeneous solution, which exhibited quick responsiveness after simple mixing.
研究领域:
生物化学
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分析化学
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食品安全
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产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）