NANO
·
2017
·
IF 1.025
Xiqing Liu,Xiao Wei,Yeqing Xu,Hongji Li,Kai Lu,Kun Wang,Yongsheng Yan
In this paper, a novel fluorescent nanoswitch based on carbon dots (CDs) was developed for the sensitive and selective determination of Hg 2 + and I − . The CDs were obtained by simple hydrothermal process and had a strong fluorescence emission at 440 nm. The fluorescence of the CDs can be selectively quenched by Hg 2 + ion, and then the I − was added into the system, which can interact with Hg 2 + and recover fluorescence of the CDs. Under optimal conditions, the quenching fluorescence intensity on addition of Hg 2 + has obtained a satisfactory linear relationship covering the linear range of 0–50 μ M with the linear relationship ( R 1 2 = 0 . 9 9 9 1 ), and the limit of detection is 0.047 μ M. The additions of I − could lead to the fluorescence intensity of the solution of CDs and Hg 2 + (50 μ M) recover rapidly, which is linearly related ( R 2 2 = 0 . 9 9 5 7 ) to the concentration of I − in the range from 0 to 70 μ M, the detection limit for I − was calculated to be 0.084 μ M. Moreover, the developed method to detect Hg 2 + and I − was evaluated in real examples, and the fluorescence switching can sensitively and selectively detect Hg 2 + and I − over some potentially interfering ions, the recoveries were up to 97.8–107.0% and 96.7–106.6%, respectively.
研究领域:
分析化学
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环境科学
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DOI
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2018
·
IF 6.434
Lei Han,Shi Gang Liu,Jia Yu Liang,Yan Jun Ju,Nian Bing Li,Hong Qun Luo
Being a common hazardous waste, 4-nitrophenol (4-NP) has caused a serious threat to humans and environment. Therefore, rapid and selective detection of 4-NP, especially using a simple and portable instrument, is highly desired for human health and environmental monitoring. Herein, we develop a novel pH-mediated reversible fluorescence nanoswitch for selectively detecting 4-NP by using water-soluble fluorescent polymer carbon dots (PCDs) as a probe. The fluorescence of PCDs can be quenched by 4-NP via inner filter effect (IFE) because its excitation spectrum well overlaps with the absorption spectrum of 4-NP under alkaline condition. However, an obvious blue shift of the absorption peak of 4-NP occurs under acidic condition, causing the fluorescence recovery of PCDs due to the disappearance of IFE. On the basis of this principle, a pH-mediated reversible fluorescence nanoswitch was constructed and a broad linear range was obtained from 0.5 to 60 μM with a detection limit of 0.26 μM for 4-NP. Furthermore, this approach was successfully applied to detect 4-NP in real water samples and a portable polyamide film-based sensor was developed for visual detection of 4-NP, which offers a promising platform for the detection of 4-NP in on-site and resource-poor settings.
研究领域:
环境科学
·
分析化学
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DOI
PubMed
高影响因子
SENSORS AND ACTUATORS B-CHEMICAL
·
2015
·
IF 4.097
Lu Jing Chai,Jin Zhou,Hui Feng,Jing Jing Lin,Zhao Sheng Qian
A convenient and reversible nanoswitch with the assistance of cerium ions based on aggregation and disaggregation of carbon quantum dots was developed to achieve highly sensitive detection of pyrophosphate ions. Two states including aggregation state and disaggregation state corresponding to fluorescence on and off signaling can be readily switched in a reversible way. The aggregation state is resulted from large nanoassembly formed by carbon quantum dots and cerium ions due to their strong complexation affinity. The disaggregation state comes from competitive combination between cerium ion and pyrophosphate ion. The PPi ion severs as the external chemical stimulus to CQDs/Ce(III) nanoassembly, and its quantity is responsive to fluorescence intensity of the sensing system. Quantitative evaluation of PPi in a broad range from 0.3 to 29.7 μM with the detection limit of 0.1 μM can be realized in this way. The PPi detection in human HeLa cells was also assessed, and fluorescence switching between ON and OFF can be readily observed in response to presence and absence of PPi.
研究领域:
分析化学
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生物传感
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纳米技术
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DOI
高影响因子
TALANTA
·
2019
·
IF 4.916
Can Chen,Fenghua Geng,Yongxiang Wang,Haidong Yu,Lin Li,Sheng Yang,Jinhua Liu,Wei Huang
The present work constructs a sequentially triggered nanoswitch (STN) for sequential detection of Cr 3+ , P 2 O 7 4− (PPi) and alkaline phosphatase (ALP) depending on polythymine (T40) templated fluorescent Cu nanoparticles (Cu NPs). A significant phenomenon is that Cr 3+ can only causing 5% QE of fluorescent Cu NPs synthesized by lower than 500 μM Cu 2+ , but the fluorescence of the Cu NPs synthesized by more than 500 μM Cu 2+ can be quenched up to 90% QE by the same concentration of Cr 3+ . Then the quenched fluorescence of CuNP-Cr 3+ complex provides a sensing platform for PPi due to the strong binding between Cr 3+ and PPi, resulting in dissociation of Cr 3+ from the surface of Cu NPs and the recovery of fluorescence emission . Further ALP hydrolysis of PPi disrupts Cr 3+ -PPi assemble and Cr 3+ is released to interact with Cu NPs, which induces fluorescence quenching again. Thus, sequentially detection of Cr 3+ (LOD, 0.03 μM), PPi (LOD, 0.005 μM) and ALP (LOD, 0.125 mU/mL) was successfully implemented with high sensitivity and selectivity. The sensor is also successfully used for Cr 3+ , PPi and ALP assays in the human serum. Additionally, the sensitive “on-off-on-off” sensing behavior of the Cu NPs allow three chemical inputs (Cr 3+ , PPi and ALP) to construct a logic gate.
研究领域:
生物化学
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分析化学
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纳米技术
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产品关联
DOI
PubMed
高影响因子
ANALYTICAL CHEMISTRY
·
2015
·
IF 5.636
Zhaosheng Qian,Lujing Chai,Qian Zhou,Yuanyuan Huang,Cong Tang,Jianrong Chen,Hui Feng
A reversible fluorescence nanoswitch by integrating carbon quantum dots nanoassembly and pyrophosphate ion is developed, and a reliable real-time fluorescent assay for acid phosphatase (ACP) activity is established on the basis of the fluorescence nanoswitch. Carbon quantum dots (CQDs) abundant in carboxyl groups on the surface, nickel(II) ion and pyrophosphate ion comprise the fluorescent nanoswitch, which operates in the following way: the nanoassembly consisting of CQDs and nickel ions can be triggered by pyrophosphate ion serving as an external stimulus. At the same time, the fluorescence nanoswitch switches between two fluorescence states (OFF and ON) accompanying shifts in their physical states aggregation and disaggregation. Based on the nanoswitch, the introduction of ACP leads to breakdown of pyrophosphate ions into phosphate ions and resultant fluorescence quenching due to catalytic hydrolysis of ACP toward pyrophosphate ions (PPi). Quantitative evaluation of ACP activity in a broad range from 18.2 U/L to 1300 U/L, with a detection limit of 5.5 U/L, can be achieved in this way, which endows the assay with sufficiently high sensitivity for practical detection in human serum and seminal plasma.
研究领域:
生物化学
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医学检验
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纳米技术
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产品关联
DOI
PubMed
高影响因子
CHEMISTRY-A EUROPEAN JOURNAL
·
2019
·Vol. 26
·期 16
·3545-3554
·
IF 5.16
Jin Yuan,Ling Wang,Yitong Wang,Jingcheng Hao
Graphical Multicolor fluorescence emission : Copper nanocluster (CuNC) assemblies with multicolor fluorescence emission and excellent reversibility were constructed on the basis of aggregation-induced emission and the solvent effect of glutathione (GSH)-capped CuNCs. On the basis of these stimuli-responsive fluorescent nanoswitches, a fluorescence sensing platform for the identification of organic solvents was designed. Copper nanoclusters (CuNCs) as a new class of fluorescent materials have attracted a great deal of interest due to their outstanding fluorescence properties. In this work, a variety of organic solvents were used to induce self-assembly of glutathione-capped CuNCs (GSH-CuNCs) to form ordered assemblies with enhanced fluorescence properties. Assemblies with multicolor fluorescence emission were constructed on the basis of the aggregation-induced emission (AIE) of GSH-CuNCs and the solvent effect. The fluorescence emission from these GSH-CuNCs assemblies can also be tuned from yellow to purple by changing the organic solvent. A possible mechanism based on the size of the assemblies and electron transfer was explored to explain the solvent effects on GSH-CuNCs. Stimuli-responsive nanoswitches with excellent reversibility can be controlled by changing the type of organic solvent and the ratio of the organic solvent to the aqueous solution of GSH-CuNCs. As the CuNCs assemblies exhibit strong, stable, and color-tunable fluorescence, they were employed as color-conversion materials for recognizing different organic solvents.
研究领域:
材料科学
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分析化学
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纳米技术
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产品关联
DOI
PubMed
高影响因子
Nanoscale
·
2019
·Vol. 11
·期 45
·21856-21866
·
IF 6.97
Hongmei Geng,Chunyang Zhou,Chunlei Guo
In this paper, we propose a strategy involving coupling DNA structural nanoswitches with toehold mediated strand displacement for constructing novel DNA-based digital comparator (DC) logic systems, which are a basic part of traditional electronic computers and can compare whether two or more input numbers are equal. However, when the number of DC inputs is increased to a certain level, the speed and quality of the computing circuit can be affected because of the limitations of conventional electronic computers when it comes to handling large-scale quantities of data. To solve this problem, in this work, we introduce a multi-input to multi-output DNA switch-based platform that can enable complex DC logical comparison. These multifunctional DNA-based switches, each including two hairpin-shaped molecular beacons and a G4/NMM complex, were used as platforms for the step-by-step realization of 2-3 DC, 3-3 DC, and 4-3 DC logic operations. Also, experiments were designed to further verify the excellent selectivity, achieving single-base mismatch operations with the digital comparator. Based on our design, comparators (“>”, “<” and “=”) can be realized. Our prototype can inspire new designs and have intelligent digital comparator and in-field applications.
研究领域:
生物化学
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分子生物学
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纳米技术
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产品关联
DOI
PubMed
高影响因子
Journal of Materials Chemistry C
·
2017
·Vol. 5
·期 11
·2826-2832
·
IF 5.256
Hang Ao,Hui Feng,Xiaolu Huang,Meizhi Zhao,Zhaosheng Qian
Dynamic covalent B–O bonds are introduced to the design of a reversible fluorescence nanoswitch in response to the external stimulus of pH. This nanoswitch is based on a phenylboronic acid functionalized carbon quantum dot (PBA–CQD) nanoprobe, and constructed with reference to the two facts that the PBA–CQD probe can bind to p-nitrophenol to form a non-fluorescent conjugate via B–O bonds, and that the making and breaking of the B–O bonds between them can be controlled by pH changes. Excellent reversibility of this nanoswitch is illustrated by switching of the pH from 4 to 8. The reaction between the PBA–CQD nanoprobe and the p-nitrophenol resulting in switching off the fluorescence is further utilized to design a general detection strategy for enzyme activity when substrates that can generate p-nitrophenol through enzymatic reactions are chosen. The feasibility of the detection strategy is qualitatively assessed using α-glucosidase and β-galactosidase, and its practicability to quantitatively monitor enzyme activity is also demonstrated by taking α-glucosidase as an example. The detection limit of this method can be as low as 0.33 U L−1, which is much lower than those reported previously and is sufficiently low to be capable of α-glucosidase level detection in practical human samples. This study demonstrates excellent usability of dynamic covalent B–O bonds in the design of reversible switches and in the general detection of enzyme activity, and provides a sensitive, real-time assay for α-glucosidase based on carbon quantum dots.
研究领域:
分析化学
·
生物医学工程
·
酶学
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DOI
高影响因子
ANALYTICA CHIMICA ACTA
·
2019
·
IF 5.256
Xuan Zhao,Wentao Li,Tong Wu,Pingping Liu,Wei Wang,Guiyun Xu,Shenghao Xu,Xiliang Luo
Herein, a zinc ion (Zn 2+ )-triggered aggregation induced emission enhancement (AIEE) fluorescence “on-off-on” nanoswitch was fabricated for inorganic pyrophosphate (PPi) and inorganic pyrophosphatase (PPase) activity detection. Dual ligand functionalized Au NCs were utilized as the substrate of the AIEE nanoswitch. The introduction of Zn 2+ can cause Au NCs aggregated along with the enhanced fluorescence. After the addition of PPi, aggregated Au NCs disaggregated along with decreased fluorescence due to the competitive combination between PPi and Zn 2+ (on-off). When PPase was introduced, PPi was hydrolyzed and release Zn 2+ , resulting in aggregated Au NCs along with enhanced fluorescence again (off-on). On the basis of this, highly selective and sensitive detection PPi (liner range from 0.1 to 300 μM) and PPase activity (liner range from 0.1 to 10 mU) can be achieved. The detection limits are 0.04 μM for PPi and 0.03 mU for PPase, respectively. Furthermore, the as-prepared Zn 2+ -triggered AIEE nanoswitch was successfully used for quantitative analysis of PPase activity in human serum with satisfactory spiked recoveries, and applied for the inhibitors screening.
研究领域:
分析化学
·
生物医学工程
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产品关联
DOI
PubMed
高影响因子
Chemistry-An Asian Journal
·
2016
·Vol. 11
·期 14
·2041-2048
·
IF 4.592
Yuehua Hu,Fan Lin,Tao Wu,Ying Wang,Xiao-Shun Zhou,Yong Shao
Graphical Stranded : Induction and selective recognition of DNA triplex assembly have been achieved by using fluorescently activated chelerythrine as a multifuncational probe (see scheme). DNA triplex assembly has attracted a variety of interest in the regulation of genetic expression, drug screening, molecular switches, and sensors. However, these achievements are essentially dependent on the formation and stability of the triplex assembly. Herein, the recognition of DNA triplex assembly with various isoquinoline alkaloids was investigated. We found that natural chelerythrine (CHE) exhibits the highest selectivity in recognizing the triplex structure. The DNA triplex stability is substantially increased upon CHE binding, as opposed to the invariance in the stability of the duplex counterpart. CHE also favors the assembly of the triplex-forming oligonucleotide (TFO) with its duplex counterpart. The triplex binding switches CHE to a strong fluorescent emitter, which suggests CHE as a useful probe in following triplex assembly. As a unique triplex selector, inducer, and emitter, CHE successfully reports the wide pH- and metal-ion-dependent tunability of the triplex nanoswitch in a label-free manner.
研究领域:
化学
·
生物化学
·
分子生物学
·
遗传学
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产品关联
DOI
PubMed
高影响因子
CARBOHYDRATE POLYMERS
·
2024
·
IF 10.7
Jianxiang Xu,Yanyan Zhang,Yilu Zheng,Tong Wang,Huan Zhang,Kai Wang,Yu Wang,Gareth R. Williams,Li-Min Zhu
In this work we present a near-infrared (NIR)-operated nanoswitch based on chitosan nanoparticles (EpCAM-CS-co-PNVCL@IR780/IMQ NPs) that induces cascade immunogenic tumor ferroptosis via cytokine storm. The formulation was prepared by loading a photosensitiser (IR780) and an immunotherapeutic drug (imiquimod; IMQ) into temperature- and pH-responsive chitosan-based NPs functionalized with tumor-targeting aptamers. The EpCAM aptamer can chaperone the NPs selectively into cancer cells, and allow them to enter the cell nucleus. In vi tr o and in vi v o assays revelaed that the NPs were able to effectively induce the immunogenic ferroptosis of cancer cells. Under NIR irradiation, EpCAM-CS-co-PNVCL@IR780/IMQ cause cell death in tumors via photothermal therapy. Moreover, IMQ promotes the maturation of dendritic cells (DCs), which then activate cytotoxic T-lymphocytes (CTLs); these T-cells go on to provide immunotherapy of metastatic tumor cells. The metastatic tumor cells can be induced to undergo ferroptosis by the addition of arachidonic acid (AA), which interacts with interferon cytokines (IFN- γ ) released from CTLs.
研究领域:
癌症治疗
·
纳米技术
·
免疫疗法
·
生物医学工程
·
药学科学
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产品关联
DOI
PubMed
高影响因子
Analytical Methods
·
2019
·Vol. 11
·期 39
·5007-5016
·
IF 2.378
Xiaofei Qin,Can Chen,Shiyu Zhang,Jixin Zhu,Yongxiang Wang,Jinhua Liu
3,3′,5,5′-Tetramethylbenzidine (TMB) is one of the traditional enzyme substrates that has been widely used in the fields of artificial enzyme mimics and natural enzymes. However, the development of TMB-based probes for fluorescence and colorimetric dual models remains a great challenge. Herein, we developed a facile method to fabricate a colorimetric and fluorescent nanoswitch based on near-infrared fluorescent TMB dots (TMBDs) for the reversible recognition (CFRR) of Fe3+ and Cys. The proposed CFRR nanoswitch was based on an oxidation–reduction mechanism by which the TMBDs are oxidized by Fe3+ to form ensembles and Cys reduces the ensembles to TMBDs. The CFRR nanoswitch exhibited high sensitivity for the colorimetric and fluorescent recognition of Fe3+ with limits of detection (LODs) of 0.17 μM and 7.5 μM and of Cys with LODs of 0.1 μM and 1.5 μM, respectively. The response speed was very fast, within 5 min. Moreover, two output signals, namely near-infrared fluorescent and colorimetric, were exhibited in this CFRR sensor; the recognition was reversible and retained good stability after three cycles. It is noteworthy to mention that the CFRR nanoswitch performed successfully in urine, and molecular logic gate systems were readily established. Therefore, these investigations will shed light on the development of multi-mode output signals for nanoprobes.
研究领域:
分析化学
·
纳米技术
·
生物传感器
·
材料科学
·
生物化学
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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）