MICROCHEMICAL JOURNAL
·
2018
·
IF 2.746
Bin Zhou,Xin-Yi Yang,Yong-Sheng Wang,Jie-Can Yi,Zhen Zeng,Huan Zhang,Ya-Ting Chen,Xi-Jiang Hu,Qing-Li Suo
A label-free fluorescence aptasensor based on conformational switching of aptamer induced by Cd 2+ was established for the good selective determination of Cd 2+ . The aptamer could act as a recognition element for Cd 2+ . SYBR green I (SG), as a signal reporter, can bind to the small groove of double-stranded DNA (dsDNA) constituted the aptamer and the complementary strand, establishing the dsDNA-SG complex and generating high fluorescence intensity . In the presence of Cd 2+ , the specific recognition and binging of aptamers preferentially with Cd 2+ induce free of complementary strands from dsDNA and conformational switching of aptamer from dsDNA to a stem-loop structure, fluorescence intensity of system decrease dramatically. Under the optimum experiment parameters, the aptasensor shows a good linear range from 1.12 μg L −1 to 224.82 μg L −1 and the excellent detection limit as low as 0.34 μg L −1 . The relative standard deviations (RSD) for determination of Cd 2+ (n = 8) were lower than 4%, and the recoveries were in the range of 98.57% ~ 102.49%. The use of fluorescence aptasensor has good selectivity and does not require any sample treatment or target preconcentration for the detection of Cd 2+ in real samples.
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高影响因子
ANALYTICAL CHEMISTRY
·
2017
·
IF 6.32
Jinyang Chen,Xinghu Ji,Zhike He
On the basis of an interesting experimental phenomenon, a novel and smart composite reagent consisting of double-stranded DNA-templated copper nanoparticles (dsDNA–CuNPs) and DNA intercalator (SYBR Green I) was developed and exploited for hydrogen peroxide (H2O2) detection as well as oxidase-based biosensing. The study found that, within the composite reagent, the small molecule SYBR Green I was easily adsorbed on the surfaces of CuNPs, instead of intercalating into the dsDNA. So the composite reagent only exhibited the red fluorescence generated from dsDNA–CuNPs. However, when the solution of H2O2 was added into the composite reagent, the CuNPs were deconstructed and their fluorescence was quenched; meanwhile, the inhibition of SYBR Green I binding with dsDNA was eliminated. As a result, the mixed solution of the composite reagent with H2O2 exhibited green fluorescence generated from the intercalation of SYBR Green I into dsDNA. Since H2O2 is an important molecule and involved in various research fields, this developed composite reagent could be employed for many applications in biological analysis. As a proof-of-application demonstration, the sensitive detection of glucose was conducted. Moreover, the method was also extended to the detection of other biomolecules, such as cholesterol and horseradish peroxidase, which indicated the broad applications of the proposed sensing strategy in biomedical analysis.
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DOI
PubMed
高影响因子
FOOD CHEMISTRY
·
2022
·
IF 9.231
Pengfei Ma,Hua Ye,Hualin Guo,Xiaoyuan Ma,Lin Yue,Zhouping Wang
Herein, for the first time, a novel truncation strategy for aptamers’ sequences based on molecular docking was reported for the first time. T-2 toxin and AFB 1 aptamers were employed as models and fluorescence polarization was used to measure the affinity of aptamers. The T-2 toxin aptamer (T40) with 40 bases and the AFB 1 aptamer with 32 bases were successfully obtained with increased affinities compared with original aptamers. Meanwhile, circular dichroism, FAM-BHQ1 dual labeled T40, enzyme digestion, and molecular dynamics simulation were performed to investigate the binding mechanism between aptamer T40 and T-2 toxin. Finally, based on MnO 2 nanosheet and the fluorescence amplification effect of SYBR Green I, simplified and rapid fluorescence detection of T-2 toxin was achieved with a detection range of 0.03 nM to 30 nM, indicating the great potential of aptamer in practical detection applications.
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PubMed
高影响因子
ANALYST
·
2013
·Vol. 138
·期 17
·4737-4740
·
IF 3.969
Chenchen Ge,Junhua Chen,Wei Wu,Zhiyuan Fang,Lingbo Chen,Qi Liu,Lin Wang,Xuerong Xing,Lingwen Zeng
An enzyme-free and label-free fluorescence turn on biosensor for amplified copper(II) ion (Cu2+) detection has been constructed based on self-assembled DNA concatamers and Sybr Green I. This assay is simple, inexpensive and sensitive, enabling quantitative detection of as low as 12.8 pM Cu2+.
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PubMed
高影响因子
ANALYTICAL CHEMISTRY
·
2017
·
IF 6.32
Hao Hu,Jinyi Zhang,Yu Ding,Xinfeng Zhang,Kailai Xu,Xiandeng Hou,Peng Wu
Singlet oxygen (1O2), generated via photosensitization, has been proved to oxidize chromogenic substrates with neither H2O2 oxidation nor enzyme (horseradish peroxidase, HRP) catalysis. Of the various methods for modulation of the 1O2 generation, DNA-controlled photosensitization received great attention. Therefore, integration of the formation/deformation DNA structures with DNA-controlled photosensitization will be extremely appealing in visual biosensor developments. Here, the stable melamine-thymine complex was explored in combination with DNA-controlled photosensitization for visual detection of melamine. A T-rich single stand DNA was utilized as the recognition unit. Upon the formation of the T-M-T complex, double stand DNA was formed, which was ready for the binding of SYBR Green I and activated the photosensitization. Subsequent oxidation of TMB allowed visual detection of melamine in dairy products, with spike-recoveries ranging from 94% to 106%.
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PubMed
高影响因子
FOOD CHEMISTRY
·
2019
·
IF 5.399
Xiang-Xiu Chen,Zheng-Zhong Lin,Cheng-Yi Hong,Qiu-Hong Yao,Zhi-Yong Huang
A dichromatic label-free aptasensor was described for sulfadimethoxine (SDM) detection. Compared with the binding of SDM-aptamer to SDM, the higher affinity of aptamer to cDNA may result in the hybridization of dsDNA. In the presence of SDM, the aptamer specifically binds to SDM, leading to a blue color of AuNPs in deposit and fluorescence at 530 nm in supernatant after adding cDNA and SGI. With no target of SDM, AuNPs protected with the aptamer re-disperse in PBS with a red color, and no fluorescence occurs in supernatant. Based on the principle, SDM can be quantitatively detected through both fluorescent emission and AuNPs color changes with recoveries ranging from 99.2% to 102.0% for fish and from 99.5% to 100.5% for water samples. An analytical linear range of 2–300 ng mL −1 was achieved with the detection limits of 3.41 ng mL −1 for water and 4.41 ng g −1 for fish samples (3 σ , n = 9).
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高影响因子
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