JOURNAL OF MOLECULAR LIQUIDS
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2022
·
IF 6.633
Shujin Zhou,Kai Sheng,Na Zhang,Shideng Yuan,Ning Feng,Yuxuan Song,Jiafeng Geng,Xia Xin
An emulsion system with reversible demulsification/emulsification transition triggered by light irradiation was achieved by azo-modified copper nanoclusters Cu 3 (azopz) 3 ( Cu3 , Hazopz = (3,5-dimethyl-4-(phenyldiazole)-1H-pyrazole)) in the surfactant (APG0810) oil-in-water emulsion. The phase separation behavior of the emulsion is attributed to the fibrous structures self-assembled from Cu3 in the toluene phase under 365 nm UV irradiation, which break the stability of the emulsion, resulting in the demulsification. Further visible light irradiation and homogenization could recover the emulsion. This process is completely reversible under alternating ultraviolet/visible light treatments. This study shows the first application of metal nanoclusters in controlling demulsification/emulsification by a noninvasive stimulus. Further development of sustainable chemical processes such as catalyst recycling, product separation and hydrogenation reaction is highly expected based on this research.
研究领域:
材料科学
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化学工程
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纳米技术
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高影响因子
CHEMICAL PAPERS
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2022
·Vol. 76
·期 12
·7855-7863
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IF 2.146
Zhang Shen,Jin Mei-ling,Gao Ya-xi,Li Wen-qin,Wang Xin-yu,Li Xin-xin,Qiao Jia-qi,Peng Yang
Herein, histidine, as a protective agent, was applied for the synthesis of copper nanoclusters (histidine-Cu NCs) by using ascorbic acid as an efficient reducing agent. The as-fabricated fluorescent histidine-Cu NCs displayed blue-green emission wavelength at 492 nm with the excitation of 410 nm. Using histidine-Cu NCs as a novel nanoprobe, the fluorescent “turn-off” mechanism was developed for the determination of furaltadone accompanying linear attenuation of fluorescence at 492 nm. Furaltadone acted as a quencher and ln ( F 0 / F ) value of histidine-Cu NCs had an excellent linear relationship of furaltadone concentrations (0.5–500 μM) (the F 0 and F are referred to the fluorescence intensity of probe without and with furaltadone), along with the detection limit and linear fit constant of 0.085 μM and 0.9948, respectively. The fluorescence quenching of histidine-Cu NCs demonstrated good selectivity for furaltadone over other potential control substances. The quenching mechanism might be assumed to be static quenching. This system was proved to be an appropriate detection pattern for furaltadone sensing in real medical samples.
研究领域:
分析化学
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生物医学工程
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高影响因子
Analytical Methods
·
2021
·Vol. 13
·期 24
·2659-2664
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IF 2.896
Haijian Liu,Libin Dong,Miao Wang,Guofu Huang
Herein, a novel and sensitive fluorescence method for cartap determination is established on the basis of the inner filter effect (IFE) of gold nanoparticles (Au NPs) on the fluorescence of glutathione protected Cu NCs (GSH-Cu NCs). In the presence of Au NPs, the fluorescence of GSH-Cu NCs was strongly quenched by the IFE because the absorption spectra of Au NPs overlap well with the emission spectra of GSH-Cu NCs. Upon addition of cartap, cartap could induce the aggregation of Au NPs whose absorption spectrum does not overlap with the emission spectrum of GSH-Cu NCs. Then, with the increase in cartap concentration, the IFE-decreased fluorescence was gradually recovered, realizing the fluorescence sensing of cartap. Under optimal conditions, the proposed method has a good linear relationship with cartap concentration in the range of 7–100 nM, and the detection limit is 3.34 nM. In addition, satisfactory results were obtained for cartap analysis using tap water and cabbage as real samples, which demonstrated that the method as-developed would have great practical application prospects.
研究领域:
分析化学
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环境科学
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DOI
PubMed
高影响因子
MICROCHIMICA ACTA
·
2020
·Vol. 187
·期 10
·1-9
·
IF 6.232
Jiao Mingxia,Li Yun,Jia Yuxiu,Xu Le,Xu Guiyun,Guo Yingshu,Luo Xiliang
Water-soluble Cu nanoclusters (NCs) with tunable emission were synthesized through an eco-friendly one-pot aqueous method. Blue-, green-, and red-emitting NCs with the emission peaks at 420 nm, 505 nm, and 630 nm were obtained by employing ethanediamine, cysteine, and glutathione as surface ligands, respectively. The ligand effects on the optical properties of Cu NCs were studied by the single variable method. It has been revealed by systematic characterizations that the dependence of emission color on the structures of ligands was mainly attributed to their different size-tuning effects. Glutathione has the strongest chelating ability and it can significantly reduce the monomer reactivity and thus decrease the supersaturation degree of the reaction, which is favorable for modulating Cu precursor to grow into larger NCs. In contrast, ethanediamine ligand resulted in smaller nanoclusters due to its weaker binding capability. Because of the strong emission and terrific fluorescent stability, Cu NCs capped with ethanediamine, possessing an emission peak at 420 nm when excited at a wavelength of 350 nm, were directly used for probing Hg(II) with satisfying selectivity, presenting a linear range of 0.1–5.0 mM and a detection limit of 33 μM. The sensor showed good performance in real sample analysis with recoveries ranging from 99% to 103%, and comparable accuracy with atomic fluorescence spectroscopy, manifesting the reliability of the current strategy for sensing Hg(II).
Water-soluble copper nanoclusters with blue, green, and red emissions were synthesized by employing ethanediamine, cysteine, and glutathione as surface ligands respectively, and the blue-emitting nanoclusters with strong emission and terrific stability were directly used for selectively sensing Hg 2+ .
研究领域:
材料科学
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分析化学
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环境科学
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DOI
PubMed
高影响因子
NEW JOURNAL OF CHEMISTRY
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2020
·Vol. 44
·期 40
·17296-17301
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IF 3.288
Tao Lei,Ting Huang,Tianze Wang,Peng Yu,Taiping Qing,Beixi Nie
Thiocyanate (SCN−) is a metabolite of cyanide detoxification, which is considered to be a biomarker of environmental tobacco smoke exposure. Herein, a simple, fast and label-free fluorescent sensor was developed to determine SCN− based on the in situ formation of DNA-templated fluorescent copper nanoclusters (CuNCs). Without SCN−, the Cu(II) ions in buffer were reduced by ascorbic acid and then accumulated on the DNA template, showing a high fluorescence. However, in the presence of SCN−, the Cu(II) ions reacted with thiocyanate and then the remaining unreacted Cu(II) ions were reduced by ascorbic acid, producing a small amount of the CuNCs and a weak fluorescence. Several important parameters such as the concentrations of DNA, Cu(II) ions and ascorbic acid were optimized. Under the optimized conditions, the linear range was 10–100 μM and the limit of detection (LOD) was 4.94 μM for thiocyanate assay. Due to the strong chelation between SCN− and the Cu(II) ions, high selectivity was achieved for SCN− detection by this sensor, with practical applications in real water and artificial saliva. The operation process is simple and the signal response of this method to thiocyanate is fast, within a few minutes. Therefore, the developed assay has great potential to determine thiocyanate for the assessment of water safety and human health.
研究领域:
分析化学
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生物医学工程
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环境科学
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DOI
高影响因子
MICROCHIMICA ACTA
·
2014
·Vol. 182
·期 5
·909-915
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IF 3.719
Zhong Yaping,Zhu Jingjing,Wang Qingpu,He Yu,Ge Yili,Song Congwu
We show that copper nanoclusters coated with bovine serum albumin are viable probes for fluorometric determination of Cu(II) ion. The effect is attributed to the paramagnetic nature of Cu(II) bound to BSA. The ions Hg(II) and Fe(III) also give a strong effect but can be discerned by addition of EDTA. The probe can be regenerated by adding an excess of EDTA. The method is capable of detecting Cu(II) in the 0.02–34 μM, and the limit of detection is 1nM. The method was applied to the determination of Cu(II) in spiked water samples. It is rapid, simple, and fairly sensitive. The method may also be applied to detect Hg(II) and Fe(III) if Cu(II) is absent.
BSA-coated copper nanoclusters (NCs) are added to the sample, and EDTA is then added to block potentially interfering ions. The fluorescence of the NCs increases with increasing concentration of Cu(II) ions being present.
研究领域:
分析化学
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生物化学
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DOI
高影响因子
TALANTA
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2015
·
IF 3.545
Haiyan Cao,Zhaohui Chen,Yuming Huang
This paper reports an “off-to-on” fluorescence (FL) probe for sensitively and selectively detecting phosphate ions (Pi's). Fabrication of the probe was based on the competition between Pi's and tannic acid-stabilized copper nanoclusters (TA-Cu NCs) for Eu 3+ binding. The addition of Eu 3+ ions to TA-Cu NCs triggered the aggregation of TA-Cu NCs, which quenched the FL of TA-Cu NCs. After Pi addition, the aggregated TA-Cu NCs solubilized into the aqueous solution to facilitate the Pi-triggered dispersion of TA-Cu NCs. This phenomenon was due to the stronger binding ability between Pi's and Eu 3+ than that between TA and Eu 3+ , leading to FL recovery of Cu NCs. The degree of redispersion of TA-Cu NCs was directly related to Pi concentration. Thus, Pi concentration can be quantitatively determined by the change in FL of the TA-Cu NCs dispersion. Under the optimized conditions, the change in FL presented a linear relationship with Pi concentration from 0.07 μmol L −1 to 80 μmol L −1 . The limit of detection for Pi was 9.6×10 −3 μmol L −1 at a signal-to-noise ratio of 3. For Pi determination in real samples, only 1 mL water sample was needed. The proposed probe was highly sensitive, free from the interference of other common species in aqueous media, and particularly useful for the fast and simple diagnosis of water-eutrophication extent.
研究领域:
分析化学
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环境科学
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DOI
PubMed
高影响因子
MICROCHIMICA ACTA
·
2015
·Vol. 182
·期 13
·2337-2343
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IF 3.741
Tang Qin,Yang Tingting,Huang Yuming
Copper nanoclusters (Cu-NCs) were fabricated by chemical reduction of Cu(II) ions using formaldehyde as the reductant and poly(vinyl pyrrolidone) as the protecting agent. The resulting Cu-NCs were characterized by TEM, FT-IR, UV–vis and XPS and fluorescence spectroscopy. The Cu-NCs display a luminescence quantum yield of about 13 %, and the emission peaks shift from 398 to 457 nm on increasing the excitation wavelength from 310 to 390 nm. The Cu-NCs possess a storage stability of at least 2 months and are stable in the presence of high concentrations of salt. Their fluorescence is strongly quenched by hypochlorite, while other common cations, anions and hydrogen peroxide have minor (or no) effects on fluorescence. On this basis, a fluorometric hypochlorite assay was developed that has a 0.1 μM detection limit and a linear range that extends from 1 to 30 μM. The method was successfully used to the determination of hypochlorite in local tap water samples, and the results agreed well with those obtained by a colorimetric method.
Hypochlorite ion is found to quench the fluorescence copper nanoclusters synthesized by reduction of Cu(II) ion by formaldehyde in the presence of poly(vinyl pyrrolidone) serving as protecting agent. This finding resulted in a new fluorescence assay for hypochlorite.
研究领域:
分析化学
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环境科学
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生物医学
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高影响因子
MICROCHIMICA ACTA
·
2016
·Vol. 183
·期 5
·1651-1657
·
IF 4.831
Rao Hanbing,Ge Hongwei,Lu Zhiwei,Liu Wei,Chen Ziqi,Zhang Zhaoyi,Wang Xianxiang,Zou Ping,Wang Yanying,He Hua,Zeng Xianying
We report that copper nanoclusters (CuNCs) represent a viable fluorescent probe for ascorbic acid. The CuNCs were stabilized by tannic acid and characterized by high-resolution transmission electron microscopy, X-ray photoelectron spectroscopy, UV–vis, time-correlated single photon counting and fluorescence spectroscopy. It is found that the fluorescence of CuNCs (at excitation/emission peaks of 355/430 nm) is quenched by ferric ion due to electron-transfer between CuNCs and Fe(III) ions. If ascorbic acid is added, Fe(III) is reduced to Fe(II) and quenching is suppressed. The process is completed within 5 min. Under optimal conditions, a linear relation exists between fluorescence recovery and the concentration of ascorbic acid in the 0.5 μM to 10 μM concentration range. The detection limit is 0.11 μM. The method was applied to the determination of ascorbic acid in (spiked) fruit and vegetables and gave recoveries ranging from 89 to 110 %.
The fluorescence of tannic acid stabilized copper nanoclusters (TA-CuNCs) is quenched by Fe 3+ . Upon addition of ascorbic acid (AA), the redox reaction between Fe 3+ and ascorbic acid converts Fe 3+ to Fe 2+ , and this results in a dramatic fluorescence enhancement of the probe.
研究领域:
分析化学
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生物化学
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高影响因子
SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
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2020
·
IF 3.232
Congying Shao,Chunbo Li,Cheng Zhang,Zheng Ni,Xianhu Liu,Yongxiang Wang
In the present work, we report a novel chemical approach for the synthesis of orange-red emitting copper nanoclusters (Cu NCs) using L-methionine as stabilizing agent at room temperature for the first time. The synthetic route is facile, economical and viable. The methionine stabilized copper nanoclusters (Cu NCs/Met) were thoroughly characterized by TEM , FT-IR, XPS , UV–Vis, steady state and transient fluorescence spectroscopy. The results show the synthesized Cu NCs/Met with a fluorescence quantum yield of 4.37% possessed high stability and excellent optical features such as large Stokes shift and long fluorescence lifetime (8.3 μs). Significantly, the fluorescence intensity of Cu NCs/Met could be efficiently quenched by norfloxacin (NOR) pharmaceutical. A fast and cost-effective NOR sensor was proposed employing Cu NCs/Met as the fluorescent nanoprobe, and the quenching mechanisms were attributed to inner filter effect and agglomeration-induced quenching. The developed sensor exhibited a high sensitivity and selectivity towards NOR in a wide linear range from 0.05 to 250 μM with a detection limit as low as 17 nM. Moreover, the practicability of the developed NOR sensor for real sample assay was validated with satisfactory recoveries, indicating this sensing platform with great potential for label-free pharmaceutical detection in complex systems.
研究领域:
化学
·
生物分析
·
材料科学
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PubMed
高影响因子
SENSORS AND ACTUATORS B-CHEMICAL
·
2020
·
IF 7.1
Kaiwu Zhang,Xuan Wang,Caicheng Long,Jin Xu,Zixin Jiang,Bo Feng,Peng Zhang,Junjie Fei,Taiping Qing
DNA templated fluorescent copper nanoclusters (DNA-CuNCs) have demonstrated enormous potential for biochemical analysis. However, most of them are focused on DNA-related sensing. Here, we designed a hairpin DNA/RNA chimeric chain for the formation of fluorescent CuNCs and further applied it to detect reverse transcription-associated ribonuclease H (RNase H). The DNA/RNA chimera templated copper nanoclusters (DNA/RNA-CuNCs) exhibited similar spectral properties with DNA-CuNCs. In the presence of RNase H, the RNA segment in chimera is hydrolyzed and release short oligonucleotides, which fail to synthsize fluorescent CuNCs. The capabilities for RNase H detection from complex samples and screening of inhibitors were verified. This strategy exhibited high sensitivity for RNase H with a detectable minimum concentration of 5.5 × 10 −4 U mL -1 , which is lower than the developed fluorescent methods. This work will open up new thoughts to design new template for metal nanoclusters and broaden their application in RNA-related sensing.
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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高影响因子
SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
·
2023
·
IF 4.4
Minglu Zhang,Yi Zhang,Zhi-feng Cai
Development of beneficial sensors to analyze ellagic acid concentrations is of great importance for food safety and human health. Herein, a facile and fast fluorescent probe was carried out for the excellently selective and sensitive measurement of ellagic acid in real samples through histidine protected copper nanoclusters (histidine@Cu NCs) as a nanosensor. This as-developed histidine@Cu NCs were performed through UV–vis absorption spectroscopy, fluorescence spectroscopy, transmission electron microscopy, Fourier-transform infrared spectroscopy, X-ray photoelectron spectroscopy and fluorescence lifetime analysis. The TEM image revealed that this nanomaterial had spherical features with the average diameter of 2.5 ± 0.05 nm. The blue-green fluorescence of this Cu NCs was found under the UV light. Meanwhile, the maximum excitation and emission wavelength were located at 387 nm and 488 nm. After addition of ellagic acid, the fluorescence of histidine@Cu NCs was slowly weakened with excellent linear range of 0.5–300 μM and detection limit of 0.077 μM. The fluorescence weakening mechanism of this nanosensor were attributed to the inner filter effect (IFE) and static quenching. Finally, this as-established analysis platform was successfully employed to measure ellagic acid in real samples.
研究领域:
分析化学
·
食品安全
·
生物传感
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DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）