SENSORS AND ACTUATORS B-CHEMICAL
·
2017
·
IF 5.401
Hao Lin Zou,Bang Lin Li,Hong Qun Luo,Nian Bing Li
Recently, hybrids of layered MoS 2 are highly encouraged to handle the puzzles, taken by the weakness of two-dimensional (2D) transition metal dichalcogenides (TMDC), including low conductivity and lack of active edge sites. Considering the merits of zero-dimensional (0D) nanomaterials, the emerging heterostructures based on 0D Au nanoparticles and 2D MoS 2 nanosheets (MoS 2 -NSs) are successfully obtained via a spontaneously reduced process with the addition of HAuCl 4 in exfoliated MoS 2 -NSs aqueous dispersions. Significantly, with the combination of high conductivity rate and large active surface, the synthetic effect results in a diversity of improved properties of 0D-2D heterostructures, not only exhibiting improved stability, but also remarkably enhancing the selectivity and sensitivity for electrochemically simultaneous detections of dopamine, ascorbic acid, uric acid, and nitrite. Our current achievements of 0D-2D heterostructures contribute fresh ideas to the overall development of more advanced future TMDC based sensors.
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Nano Research
·
2017
·Vol. 11
·期 1
·311-322
·
IF 7.354
Liu Liu,Jiang Hui,Wang Xuemei
Proteins are excellent templates and stabilizers for Au nanoclusters (NCs) because of their abundant thiol groups and unique internal environments. However, high-molecular weight (MW) proteins with special quaternary structures are rarely reported as such templates. Considering that proteins may afford different spatial configurations as templates for Au NCs, we focused on alkaline phosphatase, catalase, and fibrinogen (MW range from 150 to 340 kDa) as direct templates for synthesizing Au NCs. We demonstrated that both Cu 2+ and Hg 2+ could induce photoluminescence (PL) quenching of these Au NCs, while their binding mechanisms were different. Therefore, significant PL recovery by amino acids, e.g., histidine and cysteine, was observed for Cu 2+ -treated Au NCs, but not Hg 2+ -treated Au NCs, allowing for selective detection of Hg 2+ by using histidine as a masking agent. The detection ranges were 0.06–2.0 μM for Hg 2+ and 0.04–5.0 μM for Cu 2+ , with low limits of detection of 0.02 and 0.01 μM, respectively. The PL change showed opposite tendency for histidine and cysteine at higher concentrations, resulting in different PL outputs. Using dual metal ion and dual amino acid combinations, an integrated PL logic gate was fabricated. This work improves the understanding of the PL mechanisms of complicated protein-localized Au NCs.
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BIOSENSORS & BIOELECTRONICS
·
2016
·
IF 7.476
Su Liu,Yu Wang,Wei Xu,Xueqi Leng,Hongzhi Wang,Yuna Guo,Jiadong Huang
In this paper, a novel sandwich-type electrochemical aptasensor has been fabricated and applied for sensitive and selective detection of antibiotic oxytetracycline (OTC). This sensor was based on graphene-three dimensional nanostructure gold nanocomposite (GR-3D Au) and aptamer-AuNPs-horseradish peroxidase (aptamer-AuNPs-HRP) nanoprobes as signal amplification . Firstly, GR-3D Au film was modified on glassy carbon electrode only by one-step electrochemical coreduction with graphite oxide (GO) and HAuCl 4 at cathodic potentials, which enhanced the electron transfer and loading capacity of biomolecules . Then the aptamer and HRP modified Au nanoparticles provide high affinity and ultrasensitive electrochemical probe with excellent specificity for OTC. Under the optimized conditions, the peak current was linearly proportional to the concentration of OTC in the range of 5×10 −10 −2×10 −3 g L −1 , with a detection limit of 4.98×10 −10 g L −1 . Additionally, this aptasensor had the advantages in high sensitivity, superb specificity and showed good recovery in synthetic samples. Hence, the developed sandwich-type electrochemical aptasensor might provide a useful and practical tool for OTC determination and related food safety analysis and clinical diagnosis.
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高影响因子
Journal of Materials Chemistry B
·
2017
·Vol. 5
·期 22
·4221-4232
·
IF 4.543
Yeying Wang,Xijian Liu,Guoying Deng,Qian Wang,Lijuan Zhang,Qiugen Wang,Jie Lu
In this work, multifunctional polystyrene@chitosan@gold nanoparticles–Fe3O4 nanoparticles–folic acid/indocyanine green (PS@CS@Au–Fe3O4–FA/ICG) nanocomposites that can integrate diagnosis and therapy into one nanoplatform was fabricated. The constructed PS@CS@Au–Fe3O4–FA/ICG nanocomposites possessed excellent computed tomography, magnetic resonance and fluorescence imaging performances which could be used to diagnose tumor and monitor the nanocomposites’ localization in vivo. Moreover, PS@CS@Au–Fe3O4–FA/ICG nanocomposites can be delivered in a targeted manner to cancer cells by folic acid in a receptor-mediated way, and tumor growth could be efficiently inhibited, even completely ablated, under NIR irradiation. That is, the constructed PS@CS@Au–Fe3O4–FA/ICG nanocomposites had great potential for computed tomography, magnetic resonance and fluorescence imaging performances, which could be used to diagnose tumors and to monitor local therapy and fluorescence imaging-guided targeted therapy of cancer cells using nanocomposites.
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高影响因子
SYNTHETIC METALS
·
2016
·
IF 2.299
Libo Sun,Xun Sun,Yuhua Zheng,Qingquan Lin,Huijuan Su,Caixia Qi
Herein, polystyrene/polyaniline/Au (PS/PANI/Au) composites were prepared by a novel method using self-made Au(en) 2 Cl 3 as the Au source and were used as the catalysts for the reduction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP). Before the preparation of PS/PANI/Au, PS microparticles were sulfonated by the copolymerization between styrene and sodium 4-styrenesulfonate (SSS). Then self-made Au(en) 2 Cl 3 was added and Au(en) 2 3+ species were adsorbed on the surface of sulfonated PS particles due to the electrostatic attraction. The Au(en) 2 3+ was then reduced to Au nanoparticles in situ by aniline monomer. After the polymerization of the residual aniline monomer by ammonium persulfate (APS), the PS/PANI/Au composite catalysts were obtained. The morphology and structure of the as-prepared PS/PANI/Au composites were characterized by TEM, FT-IR, XPS and EDX. Their catalytic performance for the reduction of 4-NP by NaBH 4 was evaluated by means of UV–vis spectroscopy. The as-prepared PS/PANI/Au composites are very active for the reduction of 4-NP by virtue of the interaction between Au nanoparticles and PANI shell. The catalytic reaction obeys the pseudo-first-order reaction equations and the reaction rate constants are also calculated in this paper.
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Journal of the Taiwan Institute of Chemical Engineers
·
2016
·
IF 2.848
Huan Chen,Shihai Cao,Jinhua Yao,Fang Jiang
A novel Ag nanowires–CdS–Au (Ag NWs–CdS–Au) photocatalyst was synthesized by a two-step solvothermal method. As a metal core, thioglycolic acid (TGA) functionalized Ag NWs provided abundant active sites, facilitating the attachment of CdS ; and the excessive S 2− on the surface of CdS favored the loading of Au, leading to the well-developed combined interface of Ag NWs–CdS and CdS–Au. The combination and interaction between Ag NWs–CdS and CdS–Au was beneficial to the electron transfer in the photocatalysis. Multiple electron transfer processes happened in the Ag NWs–CdS–Au photocatalyst, enhancing charge carrier separation efficiency. Therefore, Ag NWs–CdS–Au possessed much higher photocatalytic degradation efficiency (89%) of MB than that of Ag NWs–CdS (45%) under visible light irradiation. Additionally, the Ag NWs–CdS–Au photocatalyst could absorb more visible light, favoring the generation of leuco-methylene blue (LMB) molecules, and further promoting the formation of ·OH. The finding provides a novel method to obtain bimetallic photocatalyst with separated bimetals to achieve high visible light photocatalytic activity and stability.
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ACS Applied Materials & Interfaces
·
2015
·
IF 6.723
Jian Sun,Fan Yang,Dan Zhao,Chuanxia Chen,Xiurong Yang
By means of employing 11-mercaptoundecanoic acid (11-MUA) as a reducing agent and protecting ligand, we present straightforward one-pot preparation of fluorescent Ag/Au bimetallic nanoclusters (namely AgAuNCs@11-MUA) from AgNO3 and HAuCl4 in alkaline aqueous solution at room temperature. It is found that the fluorescence of AgAuNCs@11-MUA has been selectively quenched by Cu2+ ions, and the nonfluorescence off-state of the as-prepared AgAuNCs@11-MUA–Cu2+ ensemble can be effectively switched on upon the addition of histidine and cysteine. By incorporating Ni2+ ions and N-ethylmaleimide, this phenomenon is further exploited as an integrated logic gate and a specific fluorescence turn-on assay for selectively and sensitively sensing histidine and cysteine has been designed and established based on the original noncovalent AgAuNCs@11-MUA–Cu2+ ensemble. Under the optimal conditions, histidine and cysteine can be detected in the concentration ranges of 0.25–9 and 0.25–7 μM; besides, the detection limits are found to be 87 and 111 nM (S/N = 3), respectively. Furthermore, we demonstrate that the proposed AgAuNCs@11-MUA-based fluorescent assay can be successfully utilized for biological fluids sample analysis.
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高影响因子
CATALYSIS LETTERS
·
2014
·Vol. 144
·期 6
·1001-1008
·
IF 2.291
Lin Chao,Tao Kai,Hua Dayin,Ma Zhen,Zhou Shenghu
Abstract Bimetallic Au 3 M (M = Ni, Co, Fe) nanoparticles (NPs) were synthesized by reducing a mixture of Au 3+ and metal cations (Ni 2+ , Co 2+ , Fe 3+ ) by butyllithium in the presence of oleylamine. Au 3 M NPs were then deposited onto a commercial SiO 2 support. The Au 3 M/SiO 2 samples were not particularly active in the catalytic reduction of p -nitrophenol unless they were converted into Au–MO
x
/SiO 2 after appropriate thermal treatment in air. The Au–MO
x
/SiO 2 catalysts showed good thermal stability and significantly higher p -nitrophenol conversions than Au/SiO 2 . Relevant characterization was conducted employing X-ray diffraction, transmission electron microscopy, Fourier-transform infrared spectroscopy, and ultraviolet–visible spectroscopy. Graphical Abstract
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高影响因子
BIOSENSORS & BIOELECTRONICS
·
2014
·
IF 6.451
Wenju Xu,Huayu Yi,Yali Yuan,Pei Jing,Yaqin Chai,Ruo Yuan,George S. Wilson
In this work, a sensitive electrochemical aptasensor for thrombin (TB) based on synergetic catalysis of enzyme and porous [email protected] core–shell nanostructure has been constructed. With the advantages of large surface area and outstanding catalytic performance, porous [email protected] core–shell nanostructures were firstly employed as the nanocarrier for the immobilization of electroactive toluidine blue (Tb), hemin/G-quadruplex formed by intercalating hemin into the TB aptamer (TBA) and glucose oxidase (GOx). As a certain amount of glucose was added into the detection cell, GOx rapidly catalyzed the oxidation of glucose, coupling with the local generation of H 2 O 2 in the presence of dissolved O 2 . Then, porous [email protected] nanoparticles and hemin/G-quadruplex as the peroxidase mimics efficiently catalyzed the reduction of H 2 O 2 , amplifying the electrochemical signal and improving the sensitivity. Finally, a detection limit of 0.037 pM for TB was achieved. The excellent performance of the aptasensor indicated its promising prospect as a valuable tool in simple and cost-effective TB detection in clinical application.
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Nanoscale
·
2014
·Vol. 6
·期 7
·3753-3763
·
IF 6.739
Lun Li,Liguang Dou,Hui Zhang
M3Al-layered double hydroxide (LDH, M = Mg, Ni, Co) supported Au nanoclusters (AuNCs) catalysts have been prepared for the first time by using water-soluble glutathione-capped Au nanoclusters as precursor. Detailed characterizations show that the ultrafine Au nanoclusters (ca. 1.5 ± 0.6 nm) were well dispersed on the surface of LDH with a loading of Au below ∼0.23 wt% upon synergetic interaction between AuNCs and M3Al-LDH. AuNCs/Mg3Al-LDH-0.23 exhibits much higher catalytic performance for the oxidation of 1-phenylethanol in toluene than Au/Mg3Al-LDH(DP) by the conventional deposition precipitation method and can be applied for a wide range of alcohols without basic additives. This catalyst can also be reused without loss of activity or selectivity. The AuNCs/M(= Ni, Co)3Al-LDH catalysts present even higher alcohol oxidation activity than AuNCs/Mg3Al-LDH. Particularly, AuNCs/Ni3Al-LDH-0.22 exhibits the highest activity (46 500 h−1) for the aerobic oxidation of 1-phenylethanol under solvent-free conditions attributed to its strongest Au–support synergy. The excellent activity and stability of AuNCs/M3Al-LDH catalysts render these materials promising candidates for green base-free selective oxidation of alcohols by molecular oxygen.
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Chemical Science
·
2013
·Vol. 5
·期 3
·1082-1090
·
IF 8.314
Gang Lu,Peng Zhang,Dongqing Sun,Lei Wang,Kebin Zhou,Zhi-Xiang Wang,Guo-Cong Guo
Clean gold surface is inactive toward H2, however, computations, aided by experiments, reveal that gold surface could serve as a Lewis acid coupling with Lewis bases (e.g. imine and nitrile) to construct effective frustrated Lewis pairs (FLPs) to activate H2 and subsequently to achieve hydrogenation of small imines and nitriles. The Lewis base-coupled Au FLPs avoid tight adsorption of Lewis bases to gold surface via repulsion between nitrogen lone pair and the filled d-band electrons of the gold surface. This is different from the normal FLPs that use sterically demanding groups or a molecular scaffold to prevent formation of stable Lewis acid–base complexes. The enhanced reactivity of the gold surface toward H2 is due to the synergetic catalytic effects of Lewis acid (Au surface) and the coupled Lewis base (imine or nitrile), which is supported by projected density of states (PDOS) analyses. Among Cu, Ag and Au surfaces, Au surface exhibits such reactivity most significantly, because Au is much more electronegative than Cu and Ag. The study enriches the FLP chemistry by adding a new type (heterogeneous) of FLPs and reveals a new reaction mode for gold surface.
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SENSORS AND ACTUATORS B-CHEMICAL
·
2014
·
IF 3.84
Yongling Du,Xin Gao,Xiaoliang Ye,Zhixiang Zheng,Qingliang Feng,Chunming Wang,Kaifeng Wu
The Au–SnO 2 /graphenes (GNs)-single-walled carbon nanotubes (SWCNTs) nanocomposite has been prepared through green chemistry methods. This composite material was deliberately designed to combine the virtues of metal, semiconductor, and carbon materials. Its successful formation has been confirmed by a series of characterizations, such as transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), and X-ray photoelectron spectroscopy (XPS). A new electrode based on this nanocomposite was fabricated and used as a voltammetric sensor for detection of 2-tert-butylhydroquinone (TBHQ) through cyclic voltammetry (CV) and differential pulse voltammetry (DPV) methods. Under optimized conditions, this electrode presents a linear response in a broad concentration range of 5.0 × 10 −8 to 2.3 × 10 −4 M of TBHQ, with its detection limit reaching 5.8 × 10 −8 M. This simultaneous broad-range and ultrasensitive detecting capability for TBHQ is, to our best knowledge, better than all the previously reported modified electrodes. The excellent performance is attributed to the synergistic effects among the constituent nanomaterials (GNs, SWCNTs, SnO 2 , and Au) and the unique nano-architecture of this nanocomposite.
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