Analytical Methods
·
2015
·Vol. 8
·期 2
·453-459
·
IF 1.821
Hong Zhi Zhang,Rong Sheng Li,Ni Wang,Li Qi,Cheng Zhi Huang,Jian Wang
Sensing biomolecules such as heparin sodium and lysine are of great significance. In this work, a “turn-off–on” fluorescence switching of cadmium telluride quantum dots (CdTe QDs) was designed for both heparin sodium and lysine. Even though both heparin sodium and thioglycolic acid (TGA)-capped CdTe QDs are negatively charged, they are capable of forming a self-assembly and even aggregates through hydrogen bonding, depending on the concentration of heparin sodium, which leads to the sensitive fluorescence quenching of CdTe QDs. Thus, a fluorescence ‘turn-on’ analytical method for heparin sodium sensing could be established with a detection range of 0.200–5.000 μg mL−1 and the detection limit was 0.033 μg mL−1, which is applicable to determining heparin sodium in injection samples. What's more, a sensitive and selective “turn-off–on” nanosensor was developed for lysine analysis with the detection range of 2–200 μmol L−1 and the detection limit as low as 0.146 μmol L−1. This approach offers a new, simple, fast and selective method for determining heparin sodium and lysine.
研究领域:
分析化学
·
生物医学
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DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2021
·
IF 6.707
Jie Li,Zhongteng Wang,Juan Yang,Xinming Xia,Ruobing Yi,Jie Jiang,Wei Liu,Junlang Chen,Liang Chen,Jing Xu
Fluorescence switch based on graphene quantum dots (GQDs) is of great interest in the areas of environment, medicine and data security because of their promising applications. However, the known ternary “on-off-on” fluorescent switches of GQDs are very few due to the limited effective fluorescence recovery strategies. In this work, we proposed a new cationic control strategy and designed a novel “on-off-on” fluorescence switch, i.e., GQDs-Cu 2+ /Fe 3+ /Cr 3+ -Al 3+ /Ga 3+ /In 3+ , where the fluorescence of synthesized GQDs was quenched by Fe 3+ , Cu 2+ and Cr 3+ , and subsequently was recovered by three kinds of Group IIIA ions Al 3+ , Ga 3+ and In 3+ . The corresponding recovery degree can reach up to 0.81 compared with the pristine GQDs. The XPS results combining with quantum chemical calculations illustrated that the change of π-conjugated region caused by cations dominated the quenching and recovery of fluorescence. Furthermore, based on this “on-off-on” mechanism, a kind of anti-counterfeiting stealth ink for information encryption was also suggested. This work is the first report that Group IIIA ions Al 3+ , Ga 3+ and In 3+ can be used for fluorescence recovery, and the cationic control strategy proposed here provides a new and promising strategy for the development of “on-off-on” fluorescent switch in future studies.
研究领域:
环境科学
·
医学
·
材料科学
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DOI
高影响因子
NANO
·
2021
·
IF 1.556
Chengwei Wang,Lei Li,Yamin Wu,Jiao Gu,Chaoqun Ma,Chun Zhu,Hui Gao,Ye Zhang,Yunpeng Shang,Zichen Yang,Guoqing Chen
In this paper, multifunctional nitrogen-doped carbon dots (N-CDs) were synthesized from 3,5-diaminobenzonitrile by a simple one-step hydrothermal method. The N-CDs have a high quantum yield of 67.0% in ethanol with great water solubility, temperature stability, light stability and resistance to ion interference. Experiments showed that pH has an effect on the fluorescence intensity and emission wavelength of N-CDs. Especially, the switchable fluorescence of N-CDs caused by changes of pH value could be distinguished to the naked eye. Additionally, the multifunctional N-CDs also showed a selective response to tetracycline. We studied the influence of tetracycline on the luminescence intensity of N-CDs in the concentration range of 0–1000 μ g/L. A linear equation was established in the range of 10–80 μ g/L with a limit of detection (LOD) of 3.5 μ g/L. Based on the above excellent characteristics, N-CDs are expected to be applied in the field of sensing.
研究领域:
分析化学
·
环境科学
·
材料科学
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产品关联
DOI
高影响因子
Journal of Materials Chemistry B
·
2019
·Vol. 7
·期 15
·2549-2556
·
IF 5.047
Yaping Zhong,Tao Yi
We report a one-step hydrothermal method for the preparation of fluorescent molybdenum disulfide quantum dots (MoS2 QDs) and demonstrate the feasibility of fluorescent “turn-off–on” sensing of adenosine triphosphate (ATP) by using the MoS2 QDs. MoS2 QDs having strong blue-green fluorescence at 506 nm and good water-solubility were successfully synthesized by using ammonium tetrathiomolybdate as a single precursor. The fluorescence of MoS2 QDs was first quenched by Fe3+ through the formation of a MoS2 QDs/Fe3+ complex. ATP with the ability to coordinate with Fe3+ caused the dissociation of MoS2 QDs/Fe3+, resulting in the final release of MoS2 QDs and the recovery of fluorescence through a one-step competitive chelating process that took only 10 min to reach equilibrium at room temperature (RT). Facile and rapid sensing of Fe3+ and ATP could thus be achieved through the fluorescent “turn-off–on” strategy. Good linear relationships were obtained over the concentration ranges of 0–200 μM for Fe3+ and 0–140 μM for ATP with a lowest detectable concentration of 5 μM for ATP. Satisfactory results were obtained when the method was applied to a standard addition recovery trial of ATP in human serum samples. No complex surface modification during the preparation or detection process was needed based on the fluorescent “turn-off–on” method of the MoS2 QDs, which suggests its great potential in fluorescent sensing.
研究领域:
分析化学
·
生物传感
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
SENSORS AND ACTUATORS B-CHEMICAL
·
2015
·
IF 4.097
Fanyong Yan,Dechao Shi,Tancheng Zheng,Kaiyi Yun,Xuguang Zhou,Li Chen
An “Off–On” approach for highly sensitive and selective detection of mercury ions (Hg 2+ ) and l -cysteine ( l -Cys) was demonstrated with the use of water-soluble carbon dots (CDs) as novel fluorescent probe. In this present sensing system, Hg 2+ cations can efficiently coordinate onto the surface of CDs by means of electrostatic interactions and remarkably quench the fluorescence signal of CDs as a result of the fluorescence charge transfer (turn-off). In addition, the resulting CDs-Hg 2+ system was observed to be sensitive to l -Cys due to the ability of l -Cys to coordinate with Hg 2+ and the formation of strong Hg 2+ -SR bond. When l -Cys was added, Hg 2+ combined with l -Cys rather than with CDs resulting in the remove of Hg 2+ from the surface of CDs and shielding of fluorescence quenching, and thus, a significant fluorescence restore of CDs was observed (turn-on). Under the optimized conditions, good linearity for detecting Hg 2+ was attained over the concentration range from 2 to 22 μM with a detection limit of 0.017 μM, while the concentrations of l -Cys ranging from 2 to 20 μM exhibited a linear relationship with the relative fluorescence intensity with a correlation coefficient of R 2 = 0.99329. Moreover, this CDs-based sensor was successfully applied for visual identification and quantitation of Hg 2+ and l -Cys in real water sample and fluorescence imaging of NIH-3T3 cells with satisfying resolution.
研究领域:
分析化学
·
环境科学
·
生物医学
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产品关联
DOI
高影响因子
LUMINESCENCE
·
2023
·Vol. 38
·期 10
·1729-1737
·
IF 2.9
Jiaxuan Fan,Jing Li,Wenfeng Zhou,Haixiang Gao,Runhua Lu,Hongchao Guo
Glyphosate, the most used herbicide in the world, has a residue problem that cannot be ignored. However, glyphosate itself does not have fluorescence emission and lacks the conditions for fluorescence detection. In this work, a rapid and selective fluorescence detection method of glyphosate was designed by an ‘on–off–on’ fluorescent switch based on a luminous covalent organic framework (L-COF). Only the fixed concentration of Fe 3+ as an intermediate could trigger the fluorescent switch and no incubation step was required. The proposed method showed good accuracy with a correlation coefficient of 0.9978. The method's limits of detection and quantitation were 0.88 and 2.93 μmol/L, which were lower than the maximum allowable residue limits in some regulations. Environmental water samples and tomatoes were selected as actual samples to verify the application in a complex matrix. A satisfactory mean recovery from 87% to 106% was gained. Furthermore, Fe 3+ could induce fluorescence quenching of L-COF through the photo-induced electron transfer (PET) effect, while the addition of glyphosate could block the PET effect to achieve detection. These results demonstrated the proposed method had abilities to detect glyphosate and broaden the application of L-COF.
研究领域:
分析化学
·
环境科学
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产品关联
DOI
PubMed
高影响因子
JOURNAL OF HETEROCYCLIC CHEMISTRY
·
2015
·Vol. 53
·期 1
·109-116
·
IF 0.787
Tiesheng Hu,Zhipeng Li,Tingting Wang,Heping Zeng
Four new diarylethene derivatives based on thiophene or thiazole moieties were designed and synthesized, and the structures of compounds 4a and 5a were determined by single-X-ray diffraction analysis. All of these compounds showed reversible photochromic reactions and notable fluorescence photo-switches in solution. Furthermore, diarylethenes 4a and 5a also showed good photochromism in single crystal phase. The electron-donating and electron-withdrawing substituents play the same role in the photochromic process: red-shifted absorption and fluorescence ( 1a and 2a compared with 3a ). The fluorescent modulation efficiencies of asymmetrical diarylethenes 4 and 5 were significantly enhanced compared with the similar dithienylethenes, and the fatigue resistance of 5 was much better than 4 , which showed that the diarylethene bearing electron-withdrawing group could improve its fatigue resistance.
研究领域:
有机化学
·
材料科学
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产品关联
DOI
高影响因子
JOURNAL OF FLUORESCENCE
·
2016
·Vol. 27
·期 1
·293-302
·
IF 1.601
Li Na,He Yu,Ge Yili,Song Gongwu
In this report, a novel one-step chemical reduction method was reported for synthesis of water-soluble and stable fluorescent glutathione-templated silver nanocluster (GSH-Ag NCs) with ascorbic acid as an environmental-friendly reducing agent. On the basis of an oxidoreduction-induced fluorescence quenching mechanism, the prepared GSH-Ag NCs found to act as a cheap, non-toxic and highly sensitive “turn-off” fluorophore for ascorbic acid (AA). Furthermore, the fluorescence of the fluorophore/AA system could be recovered through addition of arginine (Arg), which made the system function as a highly selective “turn-on” sensor for arginine. Therefore, a “turn-off-on” switch sensor was proposed for detection of AA and Arg. Under optimized conditions, the probe gives a fluorescent response that is linear in the 2–300 μM concentration range of AA, with a detection limit of 0.1 μM. The probe for Arg, in turn, has a linear range in the 10–180 μM concentration range, and the limit of detection is 0.5 μM. In addition, the developed method showed great accuracy when employed to detect AA and Arg in human urine and serum, which shows its great potential in biological molecular recognition applications.
研究领域:
分析化学
·
生物传感
·
医学检测
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产品关联
DOI
PubMed
高影响因子
LANGMUIR
·
2017
·
IF 3.833
Jianqiang Chen,Chenyang Zhu,Zhen Yang,Ping Wang,Yiying Yue,Takuya Kitaoka
Lack of deep understanding of nanoparticle (NP) actions at oil/water interface set an obstacle to practical applications of Pickering emulsions. Fluorescence labels fabricated by incorporation of carbon dots (CDs) into poly(N-isopropylacrylamide) (PNIPAM) matrix can not only mark the action of PNIPAM-based NPs in the interface but also reflect the colloidal morphologies of PNIPAM. In this work, we employed coaxial electrospraying for fabricating core–shell nanospheres of cellulose acetate encapsulated by PNIPAM, and facile incorporation of CDs in PNIPAM shells was achieved simultaneously. The coaxial electrosprayed NPs (CENPs) with temperature-dependent wettability can stabilize heptane and toluene in water at 25 °C, respectively, and reversible emulsion break can be triggered by temperature adjustment around the low critical solution temperature (LCST). Remarkably, CENP/CD composites exhibited a fluorescence “on–off” behavior because of the volume phase transition of the PNIPAM shell. CENP/CD composites in Pickering emulsions clearly elucidated the motions of CENPs in response to temperature changes. At temperatures below the LCST, the CENP concentration played an important role in surface coverage of oil droplets. Specifically, the CENP concentration above the minimum concentration for complete emulsification of oil phase led to high surface coverage and two-domain adsorption of CENPs at the interface including primary monolayer anchoring of CENPs on droplets surrounded by interconnected CENP networks, which contributed to the superior stability of the emulsions. Moreover, CENP/CD composites can be recycled with well-preserved core–shell structure and stable fluorescent properties, which offers their great potential applications in sensors and imaging.
研究领域:
材料科学
·
化学工程
·
界面化学
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产品关联
DOI
PubMed
高影响因子
Polymer Chemistry
·
2016
·Vol. 7
·期 20
·3444-3450
·
IF 5.687
Dehua Li,Jinhui Jiang,Qiutong Huang,Guang Wang,Meiduo Zhang,Jianzhong Du
We report a compound polymer micelle with light-triggered “on–off” switching of fluorescence based on the self-assembly of two block copolymers. First, the naphthalimide fluorophore is incorporated into poly(styrene-stat-naphthalimide)-b-poly(N-isopropyl acrylamide) [P(St-stat-MANI)-b-PNIPAM]. Second, the naphthopyran unit is engineered in poly(styrene-stat-naphthopyran)-b-poly(N-isopropyl acrylamide) [P(St-stat-NP)-b-PNIPAM] to manipulate the fluorescence when self-assembled into compound micelles with fluorophore-containing P(St-stat-MANI)-b-PNIPAM. The fluorescence of naphthalimide (MANI) can be modulated between “on” and “off” states by the photochromic reaction of naphthopyran (NP) upon UV irradiation and thermal fading reaction. Furthermore, Nile red (NR) was encapsulated in the micelle and showed a controlled release behavior by light. Our strategy may be extended for designing a range of multifunctional smart fluorescent materials such as chemical sensors.
研究领域:
材料科学
·
化学工程
·
生物医学工程
✓ 已验证
产品关联
DOI
高影响因子
ANALYTICAL CHEMISTRY
·
2016
·
IF 5.886
Yuanyuan Huang,Weidong Liu,Hui Feng,Yangting Ye,Cong Tang,Hang Ao,Meizhi Zhao,Guilin Chen,Jianrong Chen,Zhaosheng Qian
Brightly luminescent copper nanoclusters (CuNCs) were prepared via a facile one-step synthesis in organic phase, and a novel luminescent nanoswitch on the basis of CuNCs through alternation of the physical states between aggregation and dispersion in response to specific external stimuli was designed. Two states including aggregation state and disaggregation state corresponding to fluorescence on and off signaling can be readily switched in a reversible way based on the aggregation-induced emission and disaggregation-induced quenching mechanism, respectively. This reversible nanoswitch can be controlled by the external stimulus water or N,N′-dicyclohexylcarbodiimide (DCC). The bright luminescence due to aggregation of CuNCs in organic solvents can be effectively quenched by the introduction of a small amount of water, where a disaggregation-induced quenching takes place. This specific behavior is capable to quantify an ultralow level (ppm) of water in aprotic solvents. The excellent reversibility of the nanoswitch enables one to monitor water content in a continuous and recyclable way.
研究领域:
分析化学
·
纳米科技
✓ 已验证
产品关联
DOI
PubMed
高影响因子
SENSORS AND ACTUATORS B-CHEMICAL
·
2016
·
IF 4.758
Xia Xiang,Zhen Zhang,Ling Han,Fenghong Huang,Mingming Zheng,Hu Tang,Qianchun Deng
A new fluorescence switching sensor for sensitive detection of sinapine (SP) was developed based on aggregation and disaggregation of carbon quantum dots (CDs) with the assistance of copper ions (Cu 2+ ). In the detection, carboxyl group on the surface of CDs enables the aggregation triggered by Cu 2+ due to the effective coordination, inducing obvious fluorescence quenching. Upon the addition of SP into the solution, higher affinity between SP and Cu 2+ is found to from SP-Cu coordination complex, leading to re-dispersion and fluorescence recovery of CDs. The fluorescence switching sensor for SP detection has advantages of simplicity, rapidness, high sensitivity and selectivity. The quantitative range for SP detection is from 0.04 to 5 μg mL −1 with the detection limit of 0.02 μg mL −1 . In practical samples, the recoveries of the samples ranged from 87.9% to 117.0%.
研究领域:
分析化学
·
生物化学
✓ 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）