scholarly journals A Surface Mediated Supramolecular Chiral Phenomenon for Recognition of l- and d-Cysteine

Nanomaterials ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 1027 ◽  
Author(s):  
Jing Wang ◽  
Shuai-Shuai Zhang ◽  
Xu Xu ◽  
Kai-Xuan Fei ◽  
Yin-Xian Peng
Keyword(s):  
Ag Nanoparticles ◽  
Chiral Recognition ◽  
Colloidal Solution ◽  
Total Surface Area ◽  
Chiral Molecules ◽  
Ag Nps ◽  
Sensing Platform ◽  
Bonding Interaction ◽  
Chiral Sensing ◽  
Uv Range

Chiral recognition is of fundamental importance in chemistry and life sciences and the principle of chiral recognition is instructive in chiral separation and enantioselective catalysis. Non-chiral Ag nanoparticles (NPs) conjugated with chiral cysteine (Cys) molecules demonstrate strong circular dichroism (CD) responses in the UV range. The optical activities of the l-/d-Cys capped Ag NPs are associated with the formation of order arrangements of chiral molecules on the surface of Ag NPs, which are promoted by the electrostatic attraction and hydrogen bonding interaction. The intensity of the chiroptical response is related to the total surface area of Ag NPs in the colloidal solution. The anisotropy factor on the order of 10−2 is acquired for Ag NPs with the size varying from ~2.4 to ~4.5 nm. We demonstrate a simple and effective method for the fabrication of a quantitative chiral sensing platform, in which mesoporous silica coated Ag nanoparticles (Ag@mSiO2) were used as chiral probes for recognition and quantification of Cys enantiomers.

scholarly journals Synthesis and Plasmonic Chiroptical Studies of Sodium Deoxycholate Modified Silver Nanoparticles

Materials ◽  
2018 ◽  
Vol 11 (8) ◽  
pp. 1291 ◽  
Author(s):  
Jing Wang ◽  
Kai-Xuan Fei ◽  
Xin Yang ◽  
Shuai-Shuai Zhang ◽  
Yin-Xian Peng
Keyword(s):  
Silver Nanoparticles ◽  
Ag Nanoparticles ◽  
Hot Spots ◽  
Sodium Deoxycholate ◽  
Coulomb Interactions ◽  
Chiral Molecules ◽  
Ag Nps ◽  
Line Shapes ◽  
Visible Wavelength Range ◽  
Distinct Line

Sodium deoxycholate modified silver nanoparticles prepared in the presence of sodium deoxycholate as a chiral inducer exhibit plasmonic circular dichroism (CD) signals. The plasmon-induced chirality arises from the presence of chiral molecules (sodium deoxycholate) on the surface of Ag nanoparticles, which transfer their chiral properties to the visible wavelength range due to the Coulomb interactions between the chiral molecules and plasmonic nanoparticles. The prepared Ag nanoparticles (NPs) exhibit distinct line shapes of plasmonic CD, which can be tailored by varying the pH values of the solutions. A mechanism was proposed to explain the generation of the distinct plasmonic CD shapes, which indicated that the arrangements of chiral molecules in the plasmonic hot spots between Ag NPs are crucial for the induced plasmonic CD.

scholarly journals Ag Nanoparticles Sensitized In2O3 Nanograin for the Ultrasensitive HCHO Detection at Room Temperature

2019 ◽  
Vol 14 (1) ◽  
Author(s):  
Shiqiang Zhou ◽  
Mingpeng Chen ◽  
Qingjie Lu ◽  
Yumin Zhang ◽  
Jin Zhang ◽  
...  
Keyword(s):  
Indoor Air ◽  
Ag Nanoparticles ◽  
Room Temperature ◽  
Unsolved Problem ◽  
Air Pollutant ◽  
Ag Nps ◽  
Performance Targets ◽  
Fabrication Cost ◽  
Low Concentrations ◽  
Stringent Performance

AbstractFormaldehyde (HCHO) is the main source of indoor air pollutant. HCHO sensors are therefore of paramount importance for timely detection in daily life. However, existing sensors do not meet the stringent performance targets, while deactivation due to sensing detection at room temperature, for example, at extremely low concentration of formaldehyde (especially lower than 0.08 ppm), is a widely unsolved problem. Herein, we present the Ag nanoparticles (Ag NPs) sensitized dispersed In2O3 nanograin via a low-fabrication-cost hydrothermal strategy, where the Ag NPs reduces the apparent activation energy for HCHO transporting into and out of the In2O3 nanoparticles, while low concentrations detection at low working temperature is realized. The pristine In2O3 exhibits a sluggish response (Ra/Rg = 4.14 to 10 ppm) with incomplete recovery to HCHO gas. After Ag functionalization, the 5%Ag-In2O3 sensor shows a dramatically enhanced response (135) with a short response time (102 s) and recovery time (157 s) to 1 ppm HCHO gas at 30 °C, which benefits from the Ag NPs that electronically and chemically sensitize the crystal In2O3 nanograin, greatly enhancing the selectivity and sensitivity.

A highly efficient chiral sensing platform for tryptophan isomers based on a coordination self-assembly

Talanta ◽  
2019 ◽  
Vol 195 ◽  
pp. 306-312 ◽  
Author(s):  
Peng Lei ◽  
Ying Zhou ◽  
Guomei Zhang ◽  
Yan Zhang ◽  
Caihong Zhang ◽  
...  
Keyword(s):  
Self Assembly ◽  
Highly Efficient ◽  
Sensing Platform ◽  
Chiral Sensing

scholarly journals Structural and Optical Analysis of Ag Nanoparticles assisted Vertically Aligned TiO2 Nanowires based photoanode for Dye-sensitized Solar Cells Application

2021 ◽  
Author(s):  
Biraj Shougaijam ◽  
Salam Surjit Singh
Keyword(s):  
Solar Cells ◽  
Ag Nanoparticles ◽  
Dye Sensitized Solar Cells ◽  
Visible Region ◽  
Ag Nps ◽  
Dye Sensitized ◽  
Vertically Aligned ◽  
Glad Technique ◽  
Sensitized Solar Cells ◽  
Pet Substrate

Abstract In this work, vertically aligned TiO 2 -Nanowires (TiO 2 -NWs) and Ag Nanoparticles assisted TiO 2 Nanowires (TAT-NWs) were deposited on glass and flexible PET substrates using the Glancing Angle Deposition (GLAD) technique. The morphology and structural analysis of the samples manifest the successful deposition of vertically aligned TiO 2 -NWs and TAT-NWs. The HR-TEM image of TiO 2 -NWs shows the polycrystalline nature. Further, the XRD result confirms the polycrystalline nature of both the TiO 2 -NWs and TAT-NWs samples. Besides, the HR-TEM image confirms the presence of small crystal grains of Ag Nanoparticles (Ag-NPs) at the mid of the annealed TAT-NWs. It is evident from the Selective Area Electron Diffraction (SAED) analysis of the TiO 2 -NWs and annealed TAT-NWs that the crystallinity of TiO 2 present in the annealed TAT-NWs improves after annealing. The absorption spectrum analysis of TAT-NWs deposited on glass substrate shows enhance absorption peak in the visible region with a maximum peak at ~463 nm wavelength compare to the TiO 2 -NWs, which may be attributed to the Surface Plasmon Resonance (SPR) effect of Ag-NPs. Further, it is interesting to observe that the TAT-NWs deposited on PET substrate show further absorption enhancement in the UV and visible region. In addition, the Photoluminescence analysis reveals that the bandgap of the TiO 2 -NWs is ~3.12 eV, which supports the bandgap extracted from the Tauc plot. Therefore, the proposed method of fabricating TAT-NWs on glass and flexible ITO coated PET substrate using the GLAD technique may be applicable for developing novel photoanode for Dye-sensitized Solar Cells (DSSCs) and other optoelectronic applications.

Effect of Plasmid DNA Dimension Evolution on the Size of Ag Nanoparticles during Photoirradiation

2016 ◽  
Vol 847 ◽  
pp. 194-199
Author(s):  
Jin Dan Zhang ◽  
Mei Yu ◽  
Jian Hua Liu ◽  
Song Mei Li ◽  
Yan Bing Meng
Keyword(s):  
Linear Relationship ◽  
Plasmid Dna ◽  
Ag Nanoparticles ◽  
Synthesis Process ◽  
Ag Nps ◽  
Base Pairs ◽  
Ultraviolet C ◽  
Metallic Nanomaterials ◽  
Ft Ir ◽  
Induce Condition

Under the photoirradiation, DNA works as both template and reducing agent to drive the formation of metallic nanomaterials. In this study the plasmid DNA with different base pairs was applied as biotemplate to synthesize Ag nanoparticles (NPs) by using photoirradiation approach. The evolution of DNA dimension changed during the synthesis process, and their effect on the morphology of the synthesized Ag NPs was studied by UV-Vis spectra, FT-IR spectra, Raman spectra, AFM, and TEM. It is found that the plasmid DNA shrinked twice during the synthesis, the first time happened when the Ag (I) cations neutralized the negative charge along the DNA chain, and the second time happened when plasmid DNA reduced Ag (I) induced by the ultraviolet C (254 nm) irradiation. The size of the synthesized Ag NPs showed approximately linear relationship with the dimension of plasmid DNA scaffolds under this photo-induce condition. The compaction degree of the plasmid DNA during the Ag formation was shown by the slope of the linear relationship.

Synthesis of Ag Nanoparticles-Clinoptilolite Composite by Homogeneous and Heterogeneous Nucleation

2013 ◽  
Vol 755 ◽  
pp. 97-103 ◽  
Author(s):  
A. Ruíz-Baltazar ◽  
R. Esparza ◽  
R. Pérez ◽  
G. Rosas
Keyword(s):  
Silver Nitrate ◽  
Sodium Borohydride ◽  
Heterogeneous Nucleation ◽  
Ag Nanoparticles ◽  
Natural Zeolite ◽  
Colloidal Solution ◽  
Chemical Reduction ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron

In this study, a natural zeolite clinoptilolite-type was impregnated through homogeneous and heterogeneous nucleation with silver nanoparticles. The synthesis of Ag nanoparticles was carried out by chemical reduction of silver nitrate (AgNO3) with sodium borohydride (NaBH4). In the case of homogeneous nucleation, colloidal solution of Ag nanoparticles at concentrations of 1, 2 and 4 parts per million was added and magnetically mixed with the porous material. With respect to heterogeneous nucleation, a solution of clinoptilolite and silver nitrate (0.01 M) was prepared and stirred; subsequently, the reduction of Ag was possible due to the addition of an aqueous solution of sodium borohydride. For the structural characterization, transmission electron microscopy (TEM), X-ray diffraction (XRD) and infrared spectroscopy (IR) techniques were carried out. The results were compared and discussed in both types of nucleation.

Molecular sieving property adjusted by the encapsulation of Ag nanoparticles into ZnO@ZIF-71 nanorod arrays

2019 ◽  
Vol 55 (74) ◽  
pp. 11045-11048 ◽  
Author(s):  
Tingting Zhou ◽  
Ziyu Qin ◽  
Xiaoxia Wang ◽  
Congyi Wu ◽  
Xing Tang ◽  
...  
Keyword(s):  
Ag Nanoparticles ◽  
Nanorod Arrays ◽  
Ag Nps ◽  
Molecular Sieving

Ag NPs are encapsulated into ZIF-71 serving as an adjustable molecular sieving layer to hydrogen and acetone.

Quantitative analysis of the relationship between the dispersion stability of mixed-surfactant Ag nanoparticles and their composition

RSC Advances ◽  
2015 ◽  
Vol 5 (50) ◽  
pp. 40135-40140
Author(s):  
Jianwei Jiang ◽  
In Seok Hong ◽  
Habeebullah Thajudeen ◽  
Ying Lu ◽  
Sang-Ho Kim ◽  
...  
Keyword(s):  
Quantitative Analysis ◽  
Ag Nanoparticles ◽  
Dispersion Stability ◽  
Mixed Surfactant ◽  
Ag Nps ◽  
Chain Lengths ◽  
The Relationship

The dispersion stability of Ag NPs could be greatly enhanced by mixing n-alkylcarboxylic acid surfactants with two different chain lengths.

Local Electric Field Enhancement of Neighboring Ag Nanoparticles in Surface Enhanced Raman Scattering

2013 ◽  
Vol 760-762 ◽  
pp. 801-805 ◽  
Author(s):  
Chao Yue Deng ◽  
Gu Ling Zhang ◽  
Bin Zou ◽  
Hong Long Shi ◽  
Yu Jie Liang ◽  
...  
Keyword(s):  
Electric Field ◽  
Raman Scattering ◽  
Electric Fields ◽  
Ag Nanoparticles ◽  
Surface Enhanced Raman Scattering ◽  
Ag Nps ◽  
Sers Enhancement ◽  
Surface Enhanced ◽  
Surface Enhanced Raman ◽  
Enhanced Raman Scattering

We used a simple low-temperature hydrothermal approach to synthesize Ag nanoparticles (NPs) and demonstrated their efficiency as organic molecule detectors in surface enhanced Raman Scattering (SERS). Using finite difference time domain simulation, we described an investigation on the distribution of electric fields amplitude of the neighboring Ag NPs. The enhanced electric field is confined at the interparticle gaps and the enhancement factor can be further increased with reducing the spacing between the NPs. The theoretical simulation demonstrated good consistency with the experimental measurement results, which predicts an electric fields amplitude enhancement of 115 at the center of NPs gap and an electromagnetic SERS enhancement of 108. The evidence of clear correlations between SERS enhancement and morphology distribution offer a route to develop more effective SERS substrates.

Spin-coated Ag nanoparticles onto ITO substrates for efficient improvement of polymer solar cell performance

2015 ◽  
Vol 3 (6) ◽  
pp. 1319-1324 ◽  
Author(s):  
Sihui Li ◽  
Wenhua Li ◽  
Qian Liu ◽  
Hedi Wei ◽  
Enquan Jin ◽  
...  
Keyword(s):  
Solar Cell ◽  
Ag Nanoparticles ◽  
Spin Coating ◽  
Polymer Solar Cell ◽  
Cell Performance ◽  
Ag Nps ◽  
Solar Cell Performance

The efficiency of PSCs has been greatly improved by spin-coating monodisperse Ag NPs on ITO substrates.

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