SENSORS AND ACTUATORS B-CHEMICAL
·
2024
·
IF 8
Tingting Wang,Fanghui Ma,Feng Huang,Aomei Zhang,Minghui Yang,Xiaoqing Li,Xiang Chen
Ratiometric sensors with background correction are expected to get around the interference from complicated systems. However, there is currently a scarcity of viable carriers for quickly and easily assembling fluorophores with varying fluorescence emission . In this work, we developed a novel aptamer-based ratiometric fluorescence sensor for analysis of adenosine triphosphate (ATP) based on the properties of aptamer that enable conformational transformations upon binding to the target. The carbon dots (CDs) and thioflavin T (ThT) are employed as the reference and detection signal for the ratio-dependent sensor, which are both integrated with the aptamer. The green fluorescence of ThT was initially turn-on after binding with aptamer and then quenched in the presence of ATP, whereas the red fluorescence of CDs remained practically steady. This approach exhibits remarkable selectivity and can detect ATP in the range of 0.5–60 μM with a detection limit of 0.167 μM. Moreover, the method was successfully applied to the determination of ATP in human serum as well as in A549 cells, demonstrating the potential for medical diagnostic applications.
研究领域:
生物化学
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医学诊断
·
分析化学
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DOI
高影响因子
JOURNAL OF CHEMICAL RESEARCH
·
2023
·
IF 1.4
Zhe Chen,Yunxia Wang
A label- and enzyme-free fluorescence assay based on thioflavin T–induced G-quadruplexes is developed to sensitively and specifically detect telomerase activity. Thioflavin T has a dual role as an efficient inducer and fluorescent probe, and the incorporation of thioflavin T into the thioflavin T–induced G-quadruplexes results in an intense fluorescence enhancement. In the presence of thioflavin T and K+, G-quadruplexes are formed by elongation of the telomerase substrate primer that is catalyzed by telomerase extracted from cancer cells. Thus, the telomerase activity in cancer cell extracts can be evaluated by measuring the thioflavin T fluorescence. More importantly, thioflavin T can specifically recognize and bind to G-quadruplexes, whereas it cannot recognize single- and double-stranded DNAs, which leads to the thioflavin T–based fluorescence assay exhibiting a reduced background and improved signal-to-noise ratio. As a result, the proposed assay has the linear range from 5 to 200 HeLa cells and the detection limit is 34 HeLa cells, which holds great potential for use in the detection of telomerase activity and the diagnosis of cancer.
研究领域:
生物化学
·
分子生物学
·
癌症研究
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DOI
高影响因子
SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
·
2020
·
IF 3.232
Yuanyuan Dai,Ying Zhang,Wanliang Liao,Weiping Wang,Liang Wu
A label-free fluorescence aptasensor was developed for the rapid detection of tetracycline (TET) based on G-quadruplex structure of TET aptamers and G-quadruplex specific dye Thioflavin T (ThT). The fluorescence of free ThT is essentially weak in aqueous solution, whereas it selectively identifies the G-quadruplex of aptamers to form the G-quadruplex/ThT conjugates, resulting in an enormous increase of the fluorescence intensity . However, the fluorescence intensity of G-quadruplex/ThT conjugates was drastically suppressed due to the release of free ThT from G-quadruplex/ThT conjugates after the addition of TET via specific binding with TET aptamers. The key factors affecting sensitivity and selectivity including the reaction medium, binding time of ThT to TET aptamers, incubation time between TET aptamers and TET, concentration of ThT and TET aptamers were investigated in detail. The optimal conditions were as follows: ultrapure water as reaction medium, binding time of 5 min, incubation time of 1 min, 9.0 μmol/L ThT and 0.03 μmol/L aptamers. A good linear relationship (correlation coefficient of 0.9973) was obtained between the fluorescence quenching efficiency ( F 0 − F ) / F 0 and the logarithm of TET concentration in the range of 0.01–1.0 μmol/L. The limit of detection was 0.001 μmol/L (S/N = 3). The proposed assay was applied for the detection of TET in the spiked honey and milk samples with recoveries ranging from 93.5% to 106.9%. The developed label-free fluorescence aptasensor showed advantages of high specificity, low cost and short time-consuming, illustrating potential application for on-site detection of TET in foodstuffs.
研究领域:
分析化学
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食品科学
·
生物技术
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DOI
PubMed
高影响因子
ANALYTICAL CHEMISTRY
·
2022
·
IF 8.008
Xiangui Ma,Mengmeng Lv,Fangxin Du,Cunqi Wu,Baohua Lou,Abdallah M. Zeid,Guobao Xu
Some mustard compounds (mustards) are highly toxic chemical warfare agents. Some are explored as new anticancer drugs. Therefore, the fast, selective, and sensitive detection of mustards is extremely important for public security and cancer therapy. Mustards mostly target the N7 position on the guanine bases of DNA. The guanine-rich G-quadruplex DNA (G4) has been widely studied in the sensing area, and it was found that dimeric G4 (D-G4) could dramatically light up the fluorescence intensity of thioflavin T (ThT). Based on this, we used for the first time the D-G4 DNA as a selective probe for ultrasensitive fluorescence detection of nitrogen mustard (NM). When NM occupies the N7 on guanine, it can block the formation of the D-G4 structure due to the steric hindrance, and hence, it inhibits the combination of D-G4 with ThT, leading to a sharp decrease of fluorescence intensity. The proposed reaction mechanism is proved using ultraviolet–visible (UV–Vis) spectra, circular dichroism (CD) spectra, and polyacrylamide gel electrophoresis. Herein, the concentration of D-G4/ThT used is as low as 50 nM due to its highly fluorescent performance, enabling both high sensitivity and low cost. NM can be detected with a wide linear range from 10 to 2000 nM. The detection limit of NM reaches a surprisingly low concentration of 6 nM, which is 2 or 3 orders of magnitude lower than that of previously developed fluorescence methods for mustards and simulants.
研究领域:
生物化学
·
医学检测
·
分子生物学
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DOI
PubMed
高影响因子
SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
·
2021
·
IF 4.098
Yao Chen,Ying Tang,Haifei Wang
In this contribution, fluorescence spectroscopy based on G-quadruplex formation was developed for the quantification of ATP in cell. In the absence of ATP, thioflavin T (ThT) dye can combine with the G-rich ATP aptamer to form an ATP aptamer-ThT G-quandruplex complex, resulting in the enhancement of fluorescence intensity; otherwise, fluorescence intensity of the system will weaken with the addition of ATP, because ATP has a strong affinity with G-rich ATP aptamer and can replace ThT to form an ATP aptamer-ATP complex. A calibration model based on generalized ratio quantitative analysis model was employed to mitigate the influence of scatterers and background absorbers in cell suspensions. The proposed fluorescence method was applied to the quantitative analysis of ATP in two type of cell lines, and achieved satisfactory quantitative results with accuracy comparable to that of the reference method–ATP detection kit. The limit of detection and limit of quantification of the proposed method for ATP in cell were estimated to be 0.22 and 0.66 μM, respectively. This proposed fluorescence method is highly simple and rapid, and does not require the use of fluorescent labeling.
研究领域:
生物化学
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分析化学
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产品关联
DOI
PubMed
高影响因子
BIOSENSORS & BIOELECTRONICS
·
2015
·
IF 6.409
Qiang Chen,Junfeng Zuo,Jinfeng Chen,Ping Tong,Xiujuan Mo,Lan Zhang,Jianrong Li
In this paper, a novel label-free fluorescent biosensor for terbium (ш) (Tb 3+ ) was proposed based on structural conversion of G-quadruplex DNA mediated by Thioflavin T (ThT) and Tb 3+ . In the presence of K + , ThT could bind to K + -stabilized parallel G-quadruplex, giving rise to high fluorescence intensity . Upon the addition of Tb 3+ , Tb 3+ could competitively bind to parallel G-quadruplex leading to the structural change, which resulted in fluorescence decrease. The change of fluorescence intensity (Δ F = F 0 – F ) showed a good linear response toward the concentration of Tb 3+ over the range from 1.0 pM to 10.0 µM with a limit of detection of 0.55 pM. This proposed biosensor was simple and cost-effective in design and in operation with ultrahigh sensitivity and selectivity . Thus, the proposed biosensor could be a promising candidate for monitoring ultratrace Tb 3+ in environment.
研究领域:
生物化学
·
环境科学
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DOI
高影响因子
LANGMUIR
·
2017
·
IF 3.833
Zhe Qin,Ying Sun,Baohuan Jia,Dan Wang,Yan Ma,Gang Ma
Thioflavin T (ThT) is widely used as a fluorescent probe for amyloid fibril detection. Yet the exact kinetic mechanism of ThT binding onto amyloid fibril remains elusive. Previously reported kinetic studies using ThT-fluorescence-detected kinetic design suggested two completely different ThT-binding mechanisms. In one study, a multistep sequential binding mechanism onto a single ThT-binding site was suggested. In another study, a one-step parallel binding mechanism onto multiple ThT-binding sites was suggested. The discrepancy is likely due to the incapability of ThT-fluorescence-detected kinetic design to differentiate the two above-mentioned mechanisms. Considering the weakness of the ThT-fluorescence-detected approach, we investigated the ThT-binding mechanism onto the amyloid fibril of hen egg white lysozyme (HEWL) using a new approach, ThT-absorbance-detected kinetic design. Our new results suggest that ThT binds to HEWL fibril through the one-step parallel binding mechanism. We hope our work can offer some new insights into the interactions between dye molecules and amyloid fibrils.
研究领域:
生物化学
·
分子生物学
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产品关联
DOI
PubMed
高影响因子
SENSORS AND ACTUATORS B-CHEMICAL
·
2017
·
IF 5.401
Xiao Fang Zhang,Na Li,Yu Ling,Li Tang,Nian Bing Li,Hong Qun Luo
As one of the DNA damage repair enzymes, uracil-DNA glycosylase (UDG) plays an important role in maintaining genomic integrity. By linked bridge hybridizing-induced split G-quadruplex (SQ), we demonstrate here the construction of a simple and sensitive DNA machine for the detection of UDG activity. The satisfactory split G-quadruplex sequences (SQS) were successfully selected to be the ingredients of SQ formation. In this work, UDG recognized and removed the uracil bases from the stem of hairpin DNA (HP). And then, HP with a low melting temperature hybridized with designed SQS, forming a three-way DNA structure with an SQ. With the addition of Thioflavin T, a dramatical enhancement of fluorescence intensity was presented due to the G-quadruplex/Thioflavin T complex formation. The detection limit was as low as 7.8 × 10 −3 U/mL. And we also successfully investigated the performance of UDG activity in the HeLa cell lysate. This optical DNA machine with the merits of being simple, rapid, and economical was flexibly suitable for not only active UDG assay but also diverse target detection by adjusting the recognition region of the HP.
研究领域:
生物化学
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分子生物学
·
分析化学
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产品关联
DOI
高影响因子
ANALYTICAL AND BIOANALYTICAL CHEMISTRY
·
2022
·Vol. 414
·期 20
·6149-6156
·
IF 4.478
Qin Shanshan,Chen Xuliang,Xu Zhichen,Li Tao,Zhao Shuhong,Hu Rui,Zhu Jiang,Li Ying,Yang Yunhuang,Liu Maili
Few reports are found working on the features and functions of the human telomere G-triplex (ht-G3) though the telomere G-quadruplex has been intensely studied and widely implemented to develop various biosensors. We herein report that ht-G3 lights up Thioflavin T (ThT) and establish a sensitive biosensing platform for RNA detection by introducing a target recycling strategy. An optimal condition was selected out for ht-G3 to promote ThT to generate a strong fluorescence. Accordingly, an ht-G3-based molecular beacon was successfully designed against the corresponding RNA sequence of the SARS-CoV-2 N-gene. The sensitivity for the non-amplified RNA target achieves 0.01 nM, improved 100 times over the conventional ThT–based method. We believe this ht-G3/ThT–based label-free strategy could be widely applied for RNA detection.
研究领域:
生物化学
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分子生物学
·
分析化学
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产品关联
DOI
PubMed
高影响因子
ANALYST
·
2020
·Vol. 145
·期 13
·4664-4670
·
IF 3.978
Zhifang Wu,Hui Zhou,Qianjin Han,Xuelian Lin,Dongxue Han,Xun Li
The efficient detection of illicit drugs such as cocaine continues to be important for the fight against drug trafficking. Herein, we report a one-step method for rapid and specific cocaine detection. The method is based on our finding that small-molecule Thioflavin T (ThT) can act as a fluorescence indicator, which can be bonded with the anti-cocaine aptamer (MNS-4.1) to generate an enhanced fluorescence signal. More interestingly, upon cocaine binding, the intercalated ThT can be replaced, causing a drastic fluorescence reduction. We further optimized the sequence of MNS-4.1 and a new anti-cocaine aptamer (coc.ap2-GC) was obtained. This aptamer showed a higher affinity to both ligands, which increased the ThT binding fluorescence intensity and showed the highest quenching efficiency. Based on the fluorescence change induced by competitive binding, cocaine detection could be accomplished by a “mix-and-detect” strategy within seconds. Such a label-free method exhibits high sensitivity to cocaine with a low detection limit of 250 nM. Moreover, the practical sample analysis (2.5% human urine and saliva) also exhibits good precision and high sensitivity.
研究领域:
分析化学
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毒品检测
·
生物传感器
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产品关联
DOI
PubMed
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2022
·
IF 8.025
Zhuohao Xie,Peng Li,Haonan Zhan,Liuyan Zhuang,Sijian Tao,Liehua Deng,Jiahao Huang
Efficient and accurate detection of melamine in dairy products remains a crucial yet challenging task. Herein, an allosterically modulated G-quadruplex-integrated aptamer is rationally designed with thymine-rich recognition termini for melamine binding. The detection process is facile by simply introducing the analyte into the mixture consisting of G-quadruplex aptamer probes, exonuclease III, and thioflavin T (ThT). The detection feasibility is confirmed by the polyacrylamide gel electrophoresis and fluorescence measurement results. This exonuclease III-assisted signal amplifiable approach works well in a linear range from 0.1 nM to 0.1 μM. Moreover, a detection limit as low as 83 pM is easily achieved, which is almost five orders of magnitude smaller than the maximum allowable melamine levels (about 8 μM) defined by many countries all over the world. The whole assay time for each test is no longer than 1 h. Additionally, the scheme is highly specific and satisfactory recovery rates (from 91% to 104%) are readily obtained when challenged with melamine-spiked milk samples. Therefore, the label-free, turn-on, low-cost, and time-efficient method can be used for reliable detection of melamine in an easily manipulated and ultra-sensitive manner, which may find its utilization in the field of food safety, biomedical engineering, and clinical diagnosis.
研究领域:
分析化学
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食品安全
·
生物医学工程
·
临床诊断
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DOI
PubMed
高影响因子
CHEMOMETRICS AND INTELLIGENT LABORATORY SYSTEMS
·
2021
·
IF 3.491
Min-Xi Li,Yao Chen,Zeng-Ping Chen,Ru-Qin Yu
Alkaline phosphatase (ALP) is an important diagnostic indicator of many human diseases. Its detection is of great importance in fields such as clinical diagnosis and biomedical research. In this contribution, a simple label-free fluorescence sensing method for ALP detection was designed by integrating ALP triggered hydrolysis, terminal deoxynucleotidyl transferase assisted DNA polymerization and complex formation between G-quadruplex and thioflavin T together. Furthermore, in order to mitigate the influence of matrix effects and background interference effects on the quantitative results of the proposed fluorescence sensing method encountered in the analysis of real-world complex biological samples, the probe technique-based generalized multivariate standard addition strategy (GMSA probe ) was specifically modified, and combined with the proposed fluorescence sensing method to achieve satisfactory quantitative results for ALP in cell lysate samples with accuracy comparable to that of a commercial ALP assay kit. Its limit of detection and limit of quantification values were about 0.02 and 0.07 U/L, respectively, more than 20 times lower than those of the commercial ALP assay kit. Due to its merits of simplicity, sensitivity, specificity, as well as robustness to matrix effects and background interference effects, the combination of the proposed fluorescence sensing method and the modified GMSA probe has a great potential for ALP assay in biochemical research and clinical diagnosis.
研究领域:
生物化学
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临床诊断
·
医学研究
✓ 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）