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
·
环境科学
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DOI
高影响因子
WATER RESEARCH
·
2022
·
IF 13.4
Dingyuan Liang,Xiangrui Wang,Wenhong Fan
s The entering of silver nanoparticles (Ag NPs) in natural environments constantly increases due to their widespread production and application. While the environmental behavior, impacts, and fate of Ag NPs were critically assessed, the main challenge represents continuous tracking and quantification of Ag NPs in environmental and biological matrices. A group of labeled Ag NPs with gold cores (Au@Ag NPs) was developed for distinguishing between pristine Ag NPs and their other forms, and we comprehensively compared their physicochemical properties, environmental behavior, and biological effects with unlabeled Ag NPs. The electron transfer process from the Au core to the Ag shell gradually decreased with the increase of Ag shell thickness, then the inhibition of Ag + release induced by the Au core was gradually alleviated, but the generation of superoxide radicals was intensified sharply. Then, the effect of the Au core on the dissolution capacity and free radicals’ generation significantly altered the biological toxicity of Ag NPs, and the influence degree was related to the test organism's species. Nevertheless, the Au core retained the surface properties of Ag NPs, leading to the uptake of Au@Ag NPs, entirely consistent with the behavior of unlabeled Ag NPs. These findings confirmed that Au core labeling provides new opportunities for tracking Ag NPs in environmental and biological systems, and the exposure conditions and test organisms should be carefully assessed before employing the Au core labeling technology.
研究领域:
环境科学
·
纳米生物学
·
毒理学
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DOI
高影响因子
Science China-Materials
·
2024
·
IF 6.8
Chai Jin,Qu Changzhen,Li Kunpeng,Liang Jiaheng,Zhou Qian,Zhuang Rong,Wang Shuo,Xu Fei,Jia Qingyan,Li Peng
Highly pathogenic-resistant bacteria infections seriously hinder the wound healing process and induce a catastrophic threat to human health. Incorporating multiple antibacterial strategies into nanostructured materials has been verified to possess paramount promise for ameliorating therapeutic efficiency against resistant bacteria. Herein, a multifunctional yolk–shell nanocomposite (Au@HCN) comprised of an aurum (Au) core and hollow carbon nanosphere (HCN) shell was prepared via one-step copolymerization and carbonization. The electron plunder by Au@HCN on the bacterial membrane leads to bacterial membrane depolarization and enhanced reactive oxygen species (ROS) metabolism, resulting in remarkable efficacy against drug-resistant bacteria under dark conditions. Moreover, the synergetic photothermal therapy (PTT) displayed significant antibacterial properties (∼98%) when exposed to near-infrared (NIR) irradiation in vitro . Meanwhile, efficient eradication of drug-resistant bacteria in the infected wound in vivo was observed under NIR exposure, thereby promoting wound healing through the prominent antibacterial properties of Au@HCN. The yolk–shell Au@HCN possesses tremendous potential for combating multidrug resistance with high efficiency.
研究领域:
生物医学工程
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纳米医学
·
感染生物学
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产品关联
DOI
高影响因子
FOOD AND AGRICULTURAL IMMUNOLOGY
·
2022
·
IF 3.268
Peizhen Li,Xiuhua Xia,Jiannan Chen,Hang Yu,Yunfei Xie,Yahui Guo,Weirong Yao,He Qian,Yuliang Cheng
Gold-coated silver core–shell nanoparticles (Ag@Au NPs) have been widely used for SERS analysis due to plasmon resonance performances. However, it is a great challenge to fabricate Ag@Au core–shell structures with specified morphology. In this paper, the size and shape of Ag NPs (core) were precisely controlled by a seed-mediated approach, and then the gold shell was completely coated on under the strong reduction of ascorbic acid, resulting in Ag@Au NPs with highly regulated morphology. The obtained Ag@Au NPs achieved a similar or even better SERS enhancement factor (EF) (up to 5.7 × 107) compared to Ag NPs, but significantly higher stability. For the rapid SERS detection of nitrofurantoin metabolite AHD, a limit of detection (LOD) as low as 1 × 10−10 M and a wide linear range from 1 × 10−4 to 1 × 10−8 M were obtained. Furthermore, recoveries for crayfish samples were from 90.5% to 108%, indicating a good performance of the presented method in real sample detection.
研究领域:
分析化学
·
食品安全
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2021
·Vol. 45
·期 6
·3059-3066
·
IF 3.591
Zhiwen Pan,Junqi Yang,Weijia Song,Puqiang Luo,Junyan Zou,Jie Peng,Bo Huang,Zhi Luo
This paper reports a two-step seed-mediated synthesis of gold core@silver shell nanoparticles (Au@Ag NPs). The plasmonic properties of Au@Ag NPs were controlled through the etching effect of H2O2 generated from the oxidation of glucose. Therefore, we used Au@Ag NPs as surface-enhanced Raman scattering (SERS) substrates and 4-mercaptobenzoic acid (4-MBA) as the Raman tag to detect glucose concentration. This method exhibits a rapid detection process (5 min), a determination range from 10−1 M to 10−6 M and a detection limit of 10−6 M, which indicate that Au@Ag NPs can serve as sensitive SERS sensors for clinical detection of blood sugar.
研究领域:
生物传感
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医学诊断
·
纳米技术
✓ 已验证
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2024
·
IF 5.8
Jiaqi Chen,Yejun Chen,Jintao Shuai,Xuegang Chen,Dawei Zhang,Xi Lu,Xiangyu Fang,Binni Zou,Xue Yu,Feng Zhao,Wei Feng
The plasmonic effect enhances light absorption in semiconductor photocatalysts, while the noble metal-semiconductor interface promotes charge carrier transfer and separation, boosting photocatalytic activity. However, current methods for synthesizing metal-core TiO 2 -shell nanoparticles face challenges, such as keeping stable and preventing aggregation. This study presents a simple and moderate synthesis method for Au@TiO 2 core-shell nanoparticles, enabling precise control over the TiO 2 shell thickness and stable photocatalytic performance. Various characterization techniques were employed to assess the optical and structural properties of the synthesized Au@TiO 2 core-shell nanostructures. The results demonstrated that increasing the Au core concentration led to a gradual decrease in TiO 2 shell thickness. The adsorption properties and photocatalytic degradation efficiency of the synthesized Au@TiO 2 core-shell nanostructured catalysts were thoroughly examined, particularly focusing on their performance with methyl orange (MO) and methylene blue (MB). Au@TiO 2 achieved excellent adsorption performance for MO, with a maximum capacity of 231±6 mg/g. Furthermore, Au@TiO 2 exhibited higher photocatalytic degradation activity of both MO and MB than pure TiO 2 . The mechanism study indicated that it attributed to enhanced visible light absorption, reduced bandgap, and higher valence band energy. Additionally, the Au@TiO 2 catalysts showed good cyclic stability, making them promising for future applications. This research offers insights into designing efficient photocatalysts, addressing existing synthesis challenges, and contributing valuable references for future advancements.
研究领域:
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2019
·
IF 5.155
Zhixiang Ye,Li Lin,Ziyang Tan,Yu-Jia Zeng,Shuangchen Ruan,Jian Ye
Gap-enhanced Raman tags (GERTs) with built-in Raman molecules show excellent surface-enhanced Raman scattering (SERS) performance and great potential for biomedical applications. In this work, we add a silver (Ag) shell to gold (Au) single-shell GERTs (Au@BDT@Au) to form Au-Ag hybrid multi-shell nanoparticles . It is found that this modification enhances the SERS performance of the NPs and that the thickness of the Ag shell is a key factor in determining the enhancement. Double-shell bimetallic GERTs with a Au core, Au shell and exterior 2 nm-thickness silver shell (Au@BDT@Au@BDT@Ag) show the best SERS performance and good photostability. Moreover, we utilize the double-shell bimetallic GERTs to develop a new kind of SERS-based lateral flow immunoassay (LFIA), acheiving limit of detection as low as 0.7 mIU/mL (0.077 ng/mL). We demonstrated a simple way to fabricate sub-100 nm multi-shell bimetallic GERTs for use as SERS probes with strong Raman signals with potential for in vivo and in vitro application as bioimaging and biosensing probes.
研究领域:
生物医学工程
·
纳米技术
·
分析化学
✓ 已验证
产品关联
DOI
高影响因子
Analytical Methods
·
2023
·Vol. 15
·期 36
·4645-4655
·
IF 3.1
Chao Sun,Li Ye,Lizheng Wang,Zhiming Hu,Jianjun Ding
Aiming at the difficulty of traditional pesticide sampling, a low-cost and convenient flexible surface enhanced Raman scattering (SERS) gold core–silver shell-sponge (Au–Ag-sponge) substrate was synthesized by chemical reduction. The SERS substrate consisted of Au–AgNPs and a melamine sponge. The sponge had a rich open pore structure, which could well “capture” Au–AgNPs, generating a large number of “hot spots”. The SERS enhancement activity of the flexible substrate was characterized with rhodamine 6G (R6G) Raman probe molecules. The substrate showed good activity to 10−12 M rhodamine 6G with an enhancement factor (EF) of 7.72 × 106. Applying this substrate to the qualitative and quantitative detection of pesticide residues, the results showed that the Raman intensity was well related to the concentration of pesticide solution with the range of 0.1–10 mg L−1 of thiram and 1–10 mg L−1 of diquat. Furthermore, the substrate was analyzed by finite difference time domain (FDTD) simulation and the results were in good agreement with the experimental results. The reason for the difference in Raman signals of pesticide molecules on the same substrate was the different binding modes of Au–AgNPs on the sponge. Finally, we pointed out the advantages of flexible substrates in the field of pesticide residues, as well as future opportunities and challenges.
研究领域:
分析化学
·
环境科学
·
农业科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2014
·
IF 2.354
Xiaoqin Li,Jinru Li,Long Jiang
Recently, the biosafety of gold nanomaterials has attracted more attention. Some consider them as an adverse factor for cell growth, whereas others regard them as biocompatible. In this work, we reported a type of silica-gold core-shell structure (SiO 2 @AuNPs) with the diameter more than 70 nm that could promote cell growth. The synthesis of SiO 2 @AuNPs adopted a step-by-step protocol involving the fabrication of silica substrate followed by their amination, the attachment of fine (about 4 nm) gold seeds, and the formation of a gold shell by reducing HAuCl 4 on seeds. The cell viability experiment indicated that AuNPs attached to silica substrate could promote the growth of HeLa cell. With increasing concentration of SiO 2 @AuNPs or the content of gold shell, the viability of co-cultured HeLa cells also increased; on the contrary, acute cytotoxicity was observed when pure 4 nm AuNPs were added. Moreover, we found that the proliferative effect could be enhanced by enlarging the size of silica substrate. Due to large SiO 2 @AuNPs not entering the cell, their nano-size concavo-convex surface was facilitated to cell adhesion, probably leading to the proliferation of HeLa cells. However, detailed mechanism responsible for cell growth is still unclear and it requires more studies. Although the mechanism remains enigmatic, the findings may have practical significance for cell proliferation, which is in great demand in numerous fields such as tissue engineering. In addition, the core-shell materials were characterized by scanning electron microscope (SEM) and energy-dispersive X-ray spectrum (EDX), and the cell viability was measured by Cell Counting Kit-8 (CCK-8).
研究领域:
生物材料学
·
细胞生物学
·
纳米医学
✓ 已验证
DOI
高影响因子
SENSORS
·
2025
·Vol. 25
·期 5
·1630
·
IF 3.5
Qiang Xu,Huiting Yin,Mei Cui,Renliang Huang,Rongxin Su
A fiber-reinforced SPR sensor based on silver-nucleated gold-shell bimetallic nanoparticles and graphene oxide was developed and applied to human IgG detection. The refractive index (RI) sensitivity of the Ag@Au/GO fiber SPR sensor is as high as 4715.9 nm/RIU in the RI range of 1.333–1.365. Staphylococcus aureus protein A (SPA) can specifically recognize and bind to the fragment crystallizable (Fc) of the antibody; it facilitates the highly targeted immobilization of the antibody. SPA and rabbit anti-human IgG were immobilized on the surface of the Ag@Au/GO fiber SPR sensor for the detection of different concentrations of human IgG with a sensitivity of 0.53 nm/μg/mL and detection limits of 0.037 μg/mL. This biosensor based on the mixed structure of GO and Ag@Au combined the common advantages of the two materials. Therefore, our study provides a simple platform for biological analysis and has a good application prospect.
研究领域:
生物传感技术
·
材料科学
·
免疫学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
BIOSENSORS & BIOELECTRONICS
·
2016
·
IF 7.476
Zongbing Li,Xiangmin Miao,Ke Xing,Xue Peng,Aihua Zhu,Liansheng Ling
A novel electrochemical biosensor for Hg 2+ detection was reported by using DNA-based hybridization chain reaction (HCR) coupled with positively charged [email protected] core-shell nanoparticles ((+) [email protected] CSNPs) amplification. To construct the sensor, capture probe (CP ) was firstly immobilized onto the surface of glass carbon electrode (GCE). In the presence of Hg 2+ , the sandwiched complex can be formed between the immobilized CP on the electrode surface and the detection probe (DP) modified on the gold nanoparticles (AuNPs) based on T-Hg 2+ -T coordination chemistry. The carried DP then opened two ferrocene (Fc) modified hairpin DNA (H 1 and H 2 ) in sequence and propagated the happen of HCR to form a nicked double-helix. Numerous Fc molecules were formed on the neighboring probe and produced an obvious electrochemical signal. Moreover, (+) [email protected] CSNPs were assembly onto such dsDNA polymers as electrochemical signal enhancer. Under optimal conditions, such sensor presents good electrochemical responses for Hg 2+ detection with a detection limit of 3.6 pM. Importantly, the methodology has high selectivity for Hg 2+ detection.
研究领域:
生物传感
·
环境科学
·
分析化学
✓ 已验证
DOI
PubMed
高影响因子
JOURNAL OF ELECTROANALYTICAL CHEMISTRY
·
2021
·
IF 4.464
Jinling Li,Tao Shao,Bowen Meng,Shijie He,Qiankun Zhang,Dongxia Zhang,Xibin Zhou
At present, Pt-based catalysts with controllable compositions , architectures, and crystal facets are still the most prevalent materials for the electro-oxidation of methanol (MOR), which is a compelling reaction in proton exchange membrane fuel cells. Herein, based on graphene quantum dots (GQDs), we report a facial and environment-friendly approach to prepare the Au@GQDs@Pt x Pb core-shell nano-pompons for the MOR in alkaline solutions. It was noticed that among all the as-synthesized samples, Au@GQDs@Pt 3.5 Pb displays an admirable activity, which is as high as 15.14 A mg −1 Pt and almost 38-fold higher than that of commercial Pt/C catalyst. And its resistance to poisoning species and long-term stability are also greatly improved. The improved performance for MOR might be attributed to the channel-rich structure of catalysts with the aid of GQDs, Au, and the electronic effect between Pt and Pb. The results indicate that the reasonable composition and structure of Au@GQDs@Pt x Pb exhibits efficient MOR, it could be a promising candidate for direct methanol fuel cells.
研究领域:
材料科学
·
电化学
·
催化反应
✓ 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）