Journal of Materials Chemistry C
·
2013
·Vol. 1
·期 39
·6355-6363
·
IF 0
Youlin Zhang,Xianggui Kong,Bin Xue,Qinghui Zeng,Xiaomin Liu,Langping Tu,Kai Liu,Hong Zhang
Applying the Stöber method to directly coat noble metal nanoparticles (NPs) such as gold (Au) and silver (Ag) NPs with silica shells presents challenges, since the noble metal NPs are not stable in alcoholic solution and have low chemical affinity for silica. This paper describes a method which uses 11-mercaptoundecanoic acid (MUA) as a linker molecule between the silica shell and the noble metal NPs. MUA binds strongly to the surface of the NPs via a metal–S bond by replacing the standard capping agents on the surface of the NPs. Upon MUA stabilization, the NPs can be transferred into alcohol solution and show chemical affinity for silica. The MUA-modified NPs can be directly coated with thickness controlled, smooth and homogeneous silica shells via the standard Stöber method by varying the amount of tetraethoxysilane (TEOS). Compared with methods reported in the literature for the coating of such particles, this method can not only be used to successfully coat citrated-stabilized Au or Ag NPs, but can also be extended to encapsulate oleylamine (OA)-stabilized Au NPs and cetyltrimethylammonium bromide (CTAB)-stabilized Au nanorods (NRs) by using MUA to displace the original ligand on the surface of the NPs. Additionally, the obtained metal@SiO2 core–shell NPs have been successfully applied as plasmonic nanoantennas for fluorescence enhancement in metal@SiO2@fluorophore NPs.
研究领域:
材料科学
·
纳米技术
·
光学
✓ 已验证
产品关联
DOI
NANOTECHNOLOGY
·
2018
·Vol. 29
·期 15
·154005
·
IF 3.404
Chunyang Dong,Songchang Hu,Mingyang Xing,Jinlong Zhang
A spatially separated, dual co-catalyst photocatalytic system was constructed by the stepwise introduction of RuO2 and Au nanoparticles (NPs) at the internal and external surfaces of a three dimensional, hierarchically ordered TiO2−SiO2 (HTSO) framework (the final photocatalyst was denoted as Au/HRTSO). Characterization by HR-TEM, EDS-mapping, XRD and XPS confirmed the existence and spatially separated locations of Au and RuO2. In CO2 photocatalytic reduction (CO2PR), Au/HRTSO (0.8%) shows the optimal performance in both the activity and selectivity towards CH4; the CH4 yield is almost twice that of the singular Au/HTSO or HRTSO (0.8%, weight percentage of RuO2) counterparts. Generally, Au NPs at the external surface act as electron trapping agents and RuO2 NPs at the inner surface act as hole collectors. This advanced spatial configuration could promote charge separation and transfer efficiency, leading to enhanced CO2PR performance in both the yield and selectivity toward CH4 under simulated solar light irradiation.
研究领域:
材料科学
·
环境科学
✓ 已验证
DOI
高影响因子
COLLOIDS AND SURFACES B-BIOINTERFACES
·
2013
·
IF 3.554
Yonghai Song,Dandan Zhong,Dan Luo,Mei Huang,Zhenzhong Huang,Hongliang Tan,Lanlan Sun,Li Wang
Better understanding of the interaction between nanoparticles (NPs) and protein is the basis for biological and biomedical applications of NPs. Water-soluble fluorescent CdS NPs have been widely used in the biological and biomedical fields and the study on effect of CdS NPs size on conformation and enzymatic activity of protein might be very important in its application. In this work, the interaction of CdS NPs with different size with type II restriction endonuclease (EcoRI) were investigated by atomic force microscopy, transmission electron microscopy, UV–vis spectroscopy, fluorescence quenching method, CD spectra, laser scanning confocal microscopy and gel electrophoresis. It was found that the equilibrium constant ( k D ) as well as the cooperativity degree of CdS NPs-EcoRI binding (Hill constant, n ) strongly depended on the CdS NPs size. The different curvature of CdS NPs surface could result in different changes of EcoRI conformation. The gel electrophoresis indicated that the decrease in α-helix content more or less affected the activity of EcoRI.
研究领域:
纳米技术
·
生物化学
·
分子生物学
✓ 已验证
DOI
PubMed
高影响因子
IEEE SENSORS JOURNAL
·
2024
·
IF 4.3
Cuixian Luo,Yimeng Dong,Yongjiao Sun,Yurong Huang,Lingrong Xue,Lifang Ren,Daming Wang,Minzhe Qin,Xinke Li
Tungsten disulfide (WS2) is emerging with dazzling visibility as a “layered material beyond graphene and molybdenum disulfide” due to its exquisite tunable electronic, surface structure, high carrier mobility, and physicochemical stability. In this article, In2O3 and Au nanoparticles (NPs) co-modified WS2 microsheets were prepared for detecting NO2 at room temperature (RT). The In2O3 and Au NPs were anchored on the surface of WS2 microsheets, which could be observed by the characterization. The NO2 sensing performance at RT was optimized by adjusting the contents of In2O3 and Au NPs. The proposed gas sensor based on Au1WIn6 (WS2 microsheets co-modified with 6 wt% In2O3 and 1 wt% Au NPs) showed the highest response (46.91 to 50 ppm NO2), limit of detection (LOD; 18.9 ppb), excellent linearity within the test range, and good stability under various relative humidity (RH), bending degrees, and bending times. The excellent result is attributed to the formation of a heterojunction, which increases the number of ionized oxygen adsorption sites and facilitates the reaction between NO2 gas and Au1WIn6. Therefore, it is believed that decorating WS2 microsheets with metal oxide and noble metal NPs is a promising strategy to improve the NO2 sensing property at RT.
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
ACS Catalysis
·
2024
·
IF 11.3
Xiaoliang Li,Liang Zhao,Mark Douthwaite,Kai Wang,Ouardia Akdim,Isaac T. Daniel,Rena Oh,Lei Liu,Zhe Wang,Fanhui Meng,Samuel Pattisson,Angeles López-Martin,Jian Yang,Xiaoyang Jerry Huang,Richard J. Lewis,Graham J. Hutchings
The spatial separation of Au and Pd nanoparticles supported on carbon has been demonstrated to be highly effective in facilitating aqueous-phase alcohol oxidation reactions, wherein OH– is the oxidant terminal for the oxidative dehydrogenation reaction. However, the application of this methodology in nonaqueous environments has not yet been explored. Supported alloyed Au–Pd nanoparticles are known to be highly active in the solvent-free oxidation of benzyl alcohol with oxygen as the terminal oxidant, leading to benzaldehyde by direct oxidation and toluene by disproportionation. Here, we show that by physically separating Au and Pd nanoparticles supported on carbon, the reaction rate for solvent-free benzyl alcohol oxidation can be further enhanced by coupling the oxidation and disproportionation reactions via H-transfer from Pd to Au.
研究领域:
化学
·
纳米材料科学
·
催化反应
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY A-CHEMISTRY
·
2019
·
IF 3.261
Zhengquan Liu,Lan Yang,Min Chen,Quansheng Chen
In this work, a label-free fluorimetric method for sensitive and selective detection of Cr(III) was developed by utilizing NaY/GdF 4 :Yb,Er upconversion nanoparticles (UCNPs) and citrate-modified silver nanoparticles (Cit-AgNPs) mixed system. The photophysical and morphological properties of the prepared UCNPs were characterized by various spectroscopic and microscopic techniques. The fluorescence of amino-modified UCNPs can be quenched due to the Cr(III) induced aggregation of Cit-AgNPs by means of inner filter effect. The observed quenching in the fluorescence intensity of the UCNPs is found to be dependent on the concentration of Cr(III). The fluorescence decreases linearly within the investigated concentration of 0.5–40 μM Cr(III) with a limit of detection 34 nM. The practical applicability of the present sensing method is ascertained by detecting Cr(III) in spiked tap water and instant tea samples.
研究领域:
分析化学
·
纳米技术
·
环境科学
✓ 已验证
DOI
高影响因子
KOREAN JOURNAL OF CHEMICAL ENGINEERING
·
2020
·Vol. 37
·期 4
·614-622
·
IF 2.69
Haleem Abdul,Syaal Sidra Bibi,Ajmal Muhammad,Ambreen Jaweria,Rauf Sajid,Ali Nasir,Muhammad Saz,Shah Afzal,Zia Muhammad Abid,Siddiq Muhammad
Here in, we demonstrate facile fabrication of silver and palladium nanoparticles in dual responsive poly(N-isopropylacrylamide- co -2-Acrylamido-2-methylpropane sulfonic acid) microgel with temperature- and pH-dependent catalytic potential. Palladium-based catalyst showed better catalytic efficiency as compared to silver-based catalyst for degradation of Rhodamine-B and P-Nitrophenol in aqueous medium under the same set of reaction conditions. The responsive nature of the microgel was found to be useful to tune the catalytic activity of the as-prepared catalysts, and reduction rate was enhanced with the pH and temperature elevation of the reaction medium; however, the increasing trend was slowed in the volume phase transition region of the microgel. Under a specific set of reaction conditions, the reduction of Rhodamine-B was as fast as 0.968 and 0.571 min −1 when catalyzed with palladium and silver based catalysts, respectively. The hydrodynamic radius of the particles of microgel support was found to be in the range of 65-180 nm when pH and temperature of the medium were varied in the range of 2-12 and 25-45, respectively. The estimated diameter of silver and palladium nanoparticles fabricated in the microgel support under the same set of reaction conditions was 9-15 and 7-11 nm, respectively.
研究领域:
材料科学
·
化学工程
·
纳米技术
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2017
·
IF 6.216
Xiaojing Zhang,Yue Zhou,Tengfei Xu,Kaiwei Zheng,Rongrong Zhang,Zhaoxue Peng,Hongzhong Zhang
In this study, a sequencing batch reactor (SBR) was operated as Anammox and used as parent reactor. Then three SBRs seeded from the parent reactor were adopted for investigating the effect of CuO, ZnO and TiO 2 nanoparticles (NPs) on nitrogen removal, microbial activity and microbial communities of Anammox. The bioactivities of anaerobic ammonia-oxidizing bacteria (AAOB) after different exposure period were detected by batch experiments. Results showed that NPs performed immediate and durable toxicity on Anammox. The nitrogen removal efficiency decreased to 2.3%, 2.9% and 14.0% from 71%, the Anammox rate decreased to 0.13, 0.16 and 0.75 from 2.76 mg h −1 g −1 VSS, and the relative abundance of AAOB decreased to 2.57%, 2.78% and 2.61% from 7.99%, respectively. CuO and ZnO NPs performed similar effect, while CuO NPs led to the most severe toxicity and lowest accumulative effect. TiO 2 NPs showed the lowest toxicity but most durable suppression on Anammox process.
研究领域:
环境工程
·
微生物学
·
污水处理
✓ 已验证
DOI
高影响因子
Analytical Methods
·
2015
·Vol. 7
·期 20
·8647-8654
·
IF 1.821
Qian Sun,Guangying Zhao,Wenchao Dou
A colorimetric immunoassay based on blue silica nanoparticles (blue-SiNPs) was developed for quantitative detection of Salmonella pullorum (S. pullorum). In this method, blue-SiNPs were synthesized by doping C.I. reactive blue 21 into silica nanoparticles using a reverse microemulsion method. Blue-SiNPs functionalized with anti-S. pullorum were employed as detection probes. Magnetic nanoparticles (MNPs), employed as supports for the immobilization of polyclonal antibodies against S. pullorum, were used as capture probes. The sandwich structures of MNP-S. pullorum-blue-SiNPs were separated with a magnet and etched with NaOH. The C.I. reactive blue 21, released from silica nanoparticles, was used as a colorimetric indicator. The absorbance of C.I. reactive blue 21 at 675 nm is proportional to the concentration of S. pullorum. Under optimal conditions, the developed colorimetric immunoassay exhibited a wide dynamic range of 4.4 × 102 CFU mL−1 to 4.4 × 107 CFU mL−1 toward S. pullorum with a detection limit of 4.4 × 101 CFU mL−1. For application of the assay, this method is not influenced by the complex matrix of practical samples. The recoveries of S. pullorum from chicken liver samples were from 94.5% to 108% with a good correlation coefficient (R2 = 0.9989) with those obtained by an official standard culture method. We also show that this colorimetric immunoassay can be carried out on a microplate reader with a 96-well plate. This method is particularly economic, simple, rapid, specific and has good stability. The new technology provided a basis for the detection of other pathogenic bacteria and viruses. Such a simple colorimetric immunoassay holds great potential as an on-site tool for clinical diagnosis of bacteria and viruses.
研究领域:
微生物学
·
纳米技术
·
诊断学
✓ 已验证
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2011
·
IF 3.068
Zibao Gan,Aiwu Zhao,Maofeng Zhang,Dapeng Wang,Wenyu Tao,Hongyan Guo,Da Li,Ming Li,Qian Gao
A facile strategy has been reported to obtain on-line fresh Ag as surface-enhanced Raman scattering (SERS) active substrates by making AgCl nanoparticles exposed to the laser beam of Raman spectrometer. The composition and morphology of AgCl nanoparticles were characterized by X-ray diffraction (XRD), UV–visible (UV–vis) spectroscopy and scanning electron microscopy (SEM). The laser-driven evolvement and possible formation mechanism of cubic AgCl nanoparticles to Ag/AgCl composites were also investigated by transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDS) and high-resolution transmission electron microscopy (HRTEM). Raman measurements demonstrate that the fresh Ag nanoparticles with a few defects have a prominent SERS sensitivity to probe molecules, such as the 4-mercaptopyridine (4-Mpy) and 4-aminothiophenol (PATP) molecules. The SERS intensity of 4-Mpy and PATP increases up to the maximum when the laser irradiation time is prolonged to 50 s, which corresponds to the defect extent and the proportion of fresh Ag in the Ag/AgCl composites. This work provides a simple, efficient and feasible approach for obtaining on-line fresh Ag as SERS substrates.
研究领域:
材料科学
·
光谱学
✓ 已验证
DOI
高影响因子
OPTICAL MATERIALS
·
2024
·
IF 3.8
Shaoxiong Qin,Zixiu Li,Yang Zhang,Jiaqi Pan,Jun Cao,Chaorong Li,Jingjing Wang
The sensitivity and stability of SERS substrates are critical in surface-enhanced Raman scattering (SERS) spectral applications. The present study describes the synthesis of Cu 2 O nanoparticles using a facile chemical method. It was observed that both glucose and NaBH 4 , employed as reducing agents, exerted significant influence on the particle size. Notably, NaBH 4 exhibited enhanced efficacy in producing nanoscale particles. Furthermore, the structural characteristics of the sample were significantly influenced by the concentration of the reducing agent NaBH 4 ; an excessive concentration resulted in the emergence of metal copper. The Cu 2 O nanoparticles, obtained through a suitable reduction process using NaBH 4 , exhibited significant SERS activity, indicating a strong chemical interaction between Cu 2 O and rhodamine 6G (R6G) molecules. The N-doped Cu 2 O nanoparticles with varying proportions were synthesized. Raman spectra analysis revealed that the 2%N–Cu 2 O nanoparticles exhibited the most significant enhancement effect. These findings suggest that doping represents an effective approach to enhance the SERS activity of semiconductor substrates. In addition, in-situ reduction reaction was employed to synthesize Cu 2 O/Ag composite nanoparticles, which exhibited outstanding SERS activity and enabled the detection of 10 −9 M R6G. The observed enhancement is mainly attributed to the synergistic effects arising from the electromagnetic enhancement provided by Ag nanoparticles and the chemical enhancement offered by Cu 2 O. This research provides a simple and cost-effective method for preparing Cu 2 O-based SERS substrates with excellent performance, offering valuable insights and approaches for enhancing SERS performance in the future.
研究领域:
材料科学
·
光谱学
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
SENSORS
·
2023
·Vol. 23
·期 20
·8536
·
IF 3.9
Yanxun Guan,Fen Xu,Lixian Sun,Yumei Luo,Riguang Cheng,Yongjin Zou,Lumin Liao,Zhong Cao
Due to the strong oxidizing properties of H2O2, excessive discharge of H2O2will cause great harm to the environment. Moreover, H2O2is also an energetic material used as fuel, with specific attention given to its safety. Therefore, it is of great importance to explore and prepare good sensitive materials for the detection of H2O2with a low detection limit and high selectivity. In this work, a kind of hydrogen peroxide electrochemical sensor has been fabricated. That is, polypyrrole (PPy) has been electropolymerized on the glass carbon electrode (GCE), and then Ag and Cu nanoparticles are modified together on the surface of polypyrrole by electrodeposition. SEM analysis shows that Cu and Ag nanoparticles are uniformly deposited on the surface of PPy. Electrochemical characterization results display that the sensor has a good response to H2O2with two linear intervals. The first linear range is 0.1–1 mM (R2= 0.9978, S = 265.06 μA/ (mM × cm2)), and the detection limit is 0.027 μM (S/N = 3). The second linear range is 1–35 mM (R2= 0.9969, 445.78 μA/ (mM × cm2)), corresponding to 0.063 μM of detection limit (S/N = 3). The sensor reveals good reproducibility (σ = 2.104), repeatability (σ = 2.027), anti-interference, and stability. The recoveries of the electrode are 99.84–103.00% (for 0.1–1 mM of linear range) and 98.65–104.80% (for 1–35 mM linear range). Furthermore, the costs of the hydrogen peroxide electrochemical sensor proposed in this work are reduced largely by using non-precious metals without degradation of the sensing performance of H2O2. This study provides a facile way to develop nanocomposite electrochemical sensors.Keywords:H2O2sensors;polypyrrole;electropolymerization;electrodeposition;Ag nanoparticle;Cu nanoparticle
研究领域:
分析化学
·
材料科学
·
环境科学
✓ 已验证
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）