Micromachines
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2023
·Vol. 14
·期 7
·1318
·
IF 3.4
Gang Li,Xuecheng Yu,Ruoyu Zhang,Qionglin Ouyang,Rong Sun,Liqiang Cao,Pengli Zhu
Copper-based nanoinks are emerging as promising low-cost alternatives to widely used silver nanoinks in electronic printing. However, the spontaneous oxidation of copper under ambient conditions poses significant challenges to its broader application. To address this issue, this paper presents an economical, large-scale, and environmentally friendly method for fabricating Cu@Ag nanoparticles (Cu@Ag NPs). The as-prepared nanoparticles exhibit a narrow size distribution of approximately 100 nm and can withstand ambient exposure for at least 60 days without significant oxidation. The Cu@Ag-based ink, with a 60 wt% loading, was screen-printed onto a flexible polyimide substrate and subsequently heat-treated at 290 °C for 15 minutes under a nitrogen atmosphere. The sintered pattern displayed a low electrical resistivity of 25.5 μΩ·cm (approximately 15 times the resistivity of bulk copper) along with excellent reliability and mechanical fatigue strength. The innovative Cu@Ag NPs fabrication method holds considerable potential for advancing large-scale applications of copper-based inks in flexible electronics.Keywords:core–shell nanoparticles;antioxidation;conductive ink;printing electronics
研究领域:
材料科学
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纳米技术
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DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2019
·
IF 8.355
Xiaofeng Dai,Wen Xu,Teng Zhang,Hongbin Shi,Tao Wang
The monodisperse Cu-Ag core-shell nanoparticles (Cu@Ag NPs) for electric conductive inks were successfully prepared by a simple two-step process consisting of thermal decomposition and galvanic displacement. It was found that 20 mol.% coverage of Ag enabled Cu@Ag NPs oxidation resisting with air. A new approach to achieve coalescence and sintering of Cu@Ag NPs at room temperature was proposed. 1-amino-2-propanol (MIPA), hydrophilic amine with a short C-chain, was first applied to replace the strong stabilizer, the strong stabilizer oleylamine (OAM) adsorbed on particles, thereby obtained preliminary agglomeration and hydrophobic -to- hydrophilic transition to improve the wetting capability of electrolyte solution on the surface of metal film. Then, the reducing electrolyte NaBH 4 solution was used as the destabilizing agent to deeply coalesce particles, and also inhibit the electrochemical corrosion. It takes only a few minutes to achieve sintering in air at room temperature. Due to the effective sintering at room temperature, the conductive patterns could be formed on thermo-sensitive substrates. The eventual resistivity was found to be as low as 36.3 μΩ·cm.
研究领域:
材料科学
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纳米技术
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产品关联
DOI
高影响因子
MICROCHIMICA ACTA
·
2017
·Vol. 184
·期 10
·3817-3823
·
IF 4.58
Li Jingjing,Wang Yuxian,Jiao Yunfei,Jia Ru,Chen Zhengbo
Under normal circumstances, chromate ions cannot oxidize core-shell Cu-Au nanoparticles (NPs) because the standard redox potential of the Cr(VI)/Cr(III) system is lower than that of Au(I)/Au. However, in the presence of a certain concentration of hydrogen bromide, the Nernst potential becomes higher than that of Au(I)/Au and Cu(II)/Cu (as calculated by the Nernst equation). Based on this finding, a colorimetric method was developed that is based on oxidative etching of Cu@Au NPs by chromate. The Cu-Au NPs have a light red color in the presence of 5 mM HBr. On addition of Cr(VI), the gold shell is rapidly etched from the surface of the Cu-Au NPs, and this is accompanied by a color change to blue. The color changes were characterized by UV-vis spectroscopy. The absorbance at 526 nm changes in the 0.4 nM to 1 μM chromate concentration range, and the detection limit is 0.21 nM.
Schematic of a highly sensitive and selective colorimetric method for detection of chromate based on the redox etching of Cu@Au nanoparticles induced by Cr(VI). The presence of HBr enables Cu@Au NPs to be oxidized by Cr 6+ .
研究领域:
分析化学
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环境科学
✓ 已验证
DOI
高影响因子
ANALYTICAL AND BIOANALYTICAL CHEMISTRY
·
2024
·
IF 3.8
Li Jing,Lu Chaofen,Yang Shufen,Xie Qing,Danzeng Qunzeng,Liu Cui,Zhou Chuan-Hua
Dopamine (DA) is a potent neuromodulator in the brain that affects a wide range of motivated behaviors. Abnormal concentration of DA is related to a variety of diseases. Hence, it is imperative to establish a rapid and precise method for quantifying DA. In this work, we integrate orange-yellow emissive carbon dots (CDs) with target-induced silver deposition on gold nanoparticles (Au NPs), forming gold/silver core-shell nanoparticles (Au@Ag NPs), to construct a fluorometric and colorimetric dual-signal sensor for sensitive detection of DA. Au NPs and silver ions (Ag + ) have minimal effect on the fluorescence of CDs. DA can reduce the silver ions to Ag(0) on the surface of the Au NPs to form a silver shell, resulting in the blue-shift of the absorbance peak from 520 to 416 nm, which overlaps with the excitation spectrum of CDs. As a result, the system color turns from pink to orange-yellow, and the fluorescence of CDs is quenched due to the strong inner filter effect. The linear range of the colorimetry is 0.5–18 μM with a limit of detection (LOD) of 0.41 μM, while the linear range for the fluorometry method is 0.5–14 μM with a LOD of 0.021 μM. This method demonstrates notable advantages including a low detection limit, rapid response time, and straightforward operation in practical samples, showing great potential in biomedical analysis. Graphical abstract
研究领域:
生物医学工程
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分析化学
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DOI
PubMed
高影响因子
EUROPEAN JOURNAL OF INORGANIC CHEMISTRY
·
2019
·Vol. 2019
·期 33
·3734-3739
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IF 2.578
Jie Hu,Mu Li,Kun Chen,Panchao Yin
Graphical A phase transfer approach to controllably assemble core-shell nanoparticles through two different sized CdSe QDs and tri-lacunary Keggin-type POMs functionalized with thiol groups. A co-assembly protocol of quantum dots (QDs)-polyoxometalates (POMs) hybrids is developed using Keggin-type POMs as surface capping ligands. Phase transfer strategy is used to prepare POM-QDs nanocomposites. These newly developed hybrid materials have been explored for their optical properties and aggregation behavior in solutions. UV/Vis and FT-IR are used to reveal the optical properties of POM-QDs. Small-angle X-ray scattering (SAXS) and transmission electron microscopy (TEM) are applied to characterize the co-assembled core-shell structures of POM-QDs complexes under different reaction conditions. A general trend to be noted is that the average photoluminescence (PL) lifetime of QDs decreases after phase transfer. The lifetime attenuation is caused by the surface property change of newly obtained POM-QDs complexes, which is resulted from the changed band edge recombination and shallow trap assisted recombination.
研究领域:
材料科学
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纳米技术
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光化学
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DOI
高影响因子
ACS Omega
·
2021
·
IF 3.512
Qiuzheng Du,Ziwei Jing,Hang Qi,Lihua Zuo,Lin Zhou,Hua He,Zhi Sun
The work described a new colorimetric sensor for the quantitative detection of clindamycin based on Au@Ag core–shell nanoparticles (Au@Ag NPs). The obtained Au@Ag NPs were characterized by transmission electron microscopy (TEM) and ultraviolet and visible spectrophotometry (UV–vis). When Au@Ag NPs were added to a clindamycin solution, it can be observed that the color immediately changed from bright yellow to gray-blue and the absorption spectrum also changed, realizing the visual detection of clindamycin. Under optimal conditions, the absorption ratio (A546/A400) of the UV–vis spectra increased linearly with the concentration of clindamycin ranging from 6.25 × 10–7 to 7.50 × 10–6 mol/L (R2 = 0.9945), with a limit of detection (LOD) of 2.00 × 10–7 mol/L and good recovery of 100.0–102.0% (relative standard deviation (RSD) < 2%). The detection process was convenient without complicated instruments. Compared with other analytes, the Au@Ag NPs detection system has good selectivity for clindamycin. In addition, the Au@Ag NPs colorimetric sensor was successfully used to determine clindamycin in human urine samples. This study provides a simple, rapid, intuitive, and low-cost visualization analysis method of clindamycin, which was helpful for the visualization detection of other targets.
研究领域:
分析化学
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纳米技术
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药物分析
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DOI
PubMed
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
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2016
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IF 3.014
Jiayi Jin,He Mei,Huimin Wu,Shengfu Wang,Qinghua Xia,Yu Ding
The Cu 2 O@Pt nanoparticles were prepared by a two-step method, using Vulcan XC-72 carbon as support (donated as Cu 2 O@Pt/C). Transmission electron microscopy , X-ray diffraction and X-ray photoelectron spectroscopy were used to characterize the resulting Cu 2 O@Pt core-shell nanoparticles. The chemically modified electrode based on Cu 2 O@Pt/C nanocomposites was employed to eliminate the interference from ascorbic acid and uric acid for the sensitive and selective determination of dopamine. The electrochemical results indicate that the Cu 2 O@Pt/C nanocomposites show better electrocatalytic activity for the oxidation of dopamine than Pt/C nanocomposites with a linear range from 10 nM to 1027.16 μM, a detection limit of 3 nM (S/N = 3) and sensitivity of 638.0 μA mM −1 cm −2 . Moreover, the sensor exhibits excellent long-time stability, good reproducibility and can be applied for practical application.
研究领域:
分析化学
·
生物医学工程
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产品关联
DOI
高影响因子
MATERIALS & DESIGN
·
2020
·
IF 6.289
Na Wang,Honggang Wang,Junfang Ren,Gui Gao,Shengsheng Chen,Gengrui Zhao,Yawen Yang,Jinqing Wang
In order to solve the problems of poor dispersibility and wettability, as well as unsatisfactory wear resistance and load capacity of polytetrafluoroethylene (PTFE) as water lubricating additive, a new type of PTFE@silica (PTFE@SiO 2 ) core-shell nanoparticles was prepared by encapsulating SiO 2 layer on the surface of PTFE via chemical bonding. Electron microscope analysis showed that the synthesized particles had well-defined core-shell morphology. Special double/multi-core structure and a reduced thickness of the intermediate shell were found, and the formation mechanisms were also explored in detail. The water contact angle measurement proved that the wettability of PTFE could be greatly enhanced by coating SiO 2 layer. The friction tests were performed to investigate the water lubrication properties of PTFE@SiO 2 additive, the results indicated that the core-shell PTFE@SiO 2 nanoparticles possessed the superior tribological properties, and the maximum friction coefficient and wear volume were respectively decreased by 75% and 99% when compared with pure water and water with PTFE/SiO 2 . Based on the analysis of worn surface, it was believed that the existence of core-shell structure and the formation of robust transfer film were the key to its excellent performance, and a possible lubrication mechanism was also proposed.
研究领域:
材料科学
·
摩擦学
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产品关联
DOI
高影响因子
International Journal of Nanomedicine
·
2024
·
IF 6.6
Yaxu Feng,Qing Sun,Pei Liu,Wei Fan,Bing Fan
Background Enterococcus faecalis (E. faecalis) is one of the main pathogens responsible for refractory root canal infections in the teeth and shows resistance against various antibacterial managements. Effective control of E. faecalis infection is a prerequisite for successful treatment of refractory apical periodontitis. This study aimed to analyze the antibacterial activity and mechanisms of Au@Ag nanoparticles (NPs) combined with photothermal therapy (PTT) against the original and Ag+-resistant E. faecalis.Methods Au@AgNPs with optimal shell thicknesses were synthesized and characterized. The antibacterial activity of Au@AgNPs with PTT against the original or Ag+-resistant E. faecalis was evaluated, and the antibiofilm activity was tested on E. faecalis biofilm on the dentin of teeth. The potential antibacterial mechanisms of Au@AgNPs combined with PTT against E. faecalis have also been studied. Moreover, its influence on dentin microhardness and cytotoxicity was assessed.Results This study revealed that Au@AgNPs combined with PTT showed enhanced antibacterial and antibiofilm effects, no negative effects on dentin microhardness, and low cytotoxicity toward human periodontal ligament cells (hPDLCs). Moreover, Au@AgNPs combined with PTT effectively inhibited the growth of Ag+-resistant E. faecalis. Its antibacterial effects may be exerted through the release of silver ions (Ag+), destruction of the cell membrane, production of reactive oxygen species (ROS) and inhibition of adenosine triphosphate (ATP) production. Hyperthermia generated by Au@AgNPs with PTT reduced membrane fluidity and enhanced Ag+ sensitivity by downregulating fabF expression. The upregulated expression of heat shock genes demonstrated that the Ag+ released from Au@AgNPs compromised the heat adaptation of E. faecalis.Conclusion PTT significantly enhanced Ag+ sensitivity of the original and Ag+-resistant E. faecalis. Au@AgNPs combined with PTT may have the potential to be developed as a new antibacterial agent to control E. faecalis infections in teeth.
研究领域:
牙科学
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纳米医学
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微生物学
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DOI
PubMed
高影响因子
Analytical Methods
·
2019
·Vol. 11
·期 23
·2960-2968
·
IF 2.378
Le Peng,Jun Zhou,Zhaoheng Liang,Yaping Zhang,Lucia Petti,Tao Jiang,Chenjie Gu,Danting Yang,Pasqule Mormile
Based on surface-enhanced Raman scattering (SERS) technology, Au@Ag@4MBA@5′-NH2-ssDNA probes and a Ag/TiO2@3′-NH2-ssDNA substrate were prepared and constructed into a sandwich structure to develop a high sensitivity bioassay of miRNA-21. The Au@Ag@4MBA@5′-NH2-ssDNA probes were prepared by immobilizing 5′-NH2-ssDNA onto the surfaces of 4MBA-labelled Au@Ag core–shell nanoparticles, and the Ag/TiO2@3′-NH2-ssDNA substrate was prepared by immobilizing 3′-NH2-ssDNA on the surface of Ag/TiO2 nanowires SERS-active substrates. The experimental results showed that the SERS-based sandwich bioassay of miRNA-21 presented a low limit of detection of 0.75 fM and a broad dynamic range from 1.0 fM to 1.0 nM. Also, the test data for the SERS-based sandwich bioassay were not only consistent with that of the real-time fluorescence quantitative polynucleotide chain reaction (RT-qPCR) method but also displayed higher detection sensitivity. It was shown that the SERS-based sandwich bioassay of miRNA-21 has importance for use in potential applications involving diagnosing clinical cancer patients.
研究领域:
生物技术
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分子诊断
·
纳米医学
✓ 已验证
DOI
高影响因子
NANOTECHNOLOGY
·
2020
·Vol. 31
·期 35
·355601
·
IF 3.551
Yanping Fang,Xiangzhe Zeng,Yuanzhi Chen,Mingwei Ji,Hongfei Zheng,Wanjie Xu,Dong-Liang Peng
Building core–shell structures is a valuable method of enhancing the oxidation-resistance performance of Cu nanoparticles for practical applications in the field of printed circuit boards. In this study, Cu@Ni core–shell nanoparticles are synthesized via an injection solution approach utilizing Cu seeds produced during the reactions to induce the epitaxial growth of Ni shells. The thickness of the Ni shell can be controlled by varying the Cu:Ni molar ratios in the injected precursor solution, whereas changing the injection rate of the Cu precursor solution affects the size of the Cu seeds and thus controls the eventual size of the core–shell nanoparticles. Thermogravimetric analysis reveals a superior thermal stability against oxidation for Cu@Ni core–shell nanoparticles, as compared with Cu nanoparticles. The oxidation resistance of Cu@Ni conductive films increases with an increase in the Ni:Cu ratio, while the conductivity increases with a decrease in the Ni:Cu ratio. A relatively low resistivity of 27.4 µΩ cm is achieved for Cu@Ni conductive films. The results demonstrate that coating Cu nanoparticles with Ni shells via epitaxial growth can form closed shells with smooth surfaces which are valuable for Cu nanoparticles in applications where oxidation resistance is a requirement .
研究领域:
材料科学
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纳米技术
✓ 已验证
DOI
高影响因子
CARBOHYDRATE POLYMERS
·
2020
·
IF 7.182
Fengxia Wang,Xu Ding,Xiaobo Niu,Xianyi Liu,Wei Wang,Ji Zhang
Although core-shell structure is favored by many applications, preparing it with green way is rarely been reported. Herein, a core-shell structured Cu@Pd-CS nanocomposite is greenly fabricated utilizing a natural chitosan and applied to glucose detection. As-obtained Cu@Pd-CS nanoparticles were characterized by transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and powder X-ray diffraction (XRD). When applied to glucose detection, the Cu@Pd-CS exhibits good stability, sensitivity and anti-interference. Moreover, it has a good linear relationship in glucose concentrations range of 0.1−1 mM with the sensitivity of 1.53 μA mM −1 cm −2 and 1−10 mM with the sensitivity of 23.00 μA mM −1 cm −2 . This work proves the practicability of building metal-based core-shell structure nanoparticles with green resources and glucose detection application.
研究领域:
材料科学
·
分析化学
·
生物医学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）