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1.
Nanotechnology ; 35(32)2024 May 23.
Artigo em Inglês | MEDLINE | ID: mdl-38688241

RESUMO

Nanoporous silver (NPS), characterized by its three-dimensional bi-continuous interpenetrating ligament channel structure, is a good candidate for surface enhanced Raman scattering (SERS), attributed to its exceptional surface-to-volume ratio and significant SERS enhancement capabilities. Here, we have successfully fabricated NPS through the dealloying ofα-terpineol (α-TPN) coated Ag55Al45alloy. The resultingα-NPS exhibits uniform ligaments and nanopore sizes, maintaining high SERS performance even after being exposed to air for more than one month. The pretreatment of precusor alloy withα-TPN is crucial not only for the formation of nanoporous structure but also for ensuring the long term stability ofα-NPS. Specifically,α-TPN functions as a surfactant, facilitating atomic diffusion to achieve a superior interconnected NPS. Furthermore, during the dealloying process, the carbonization ofα-TPN serves as a protective layer, effectively inhibiting the oxidation of silver.

2.
Nanotechnology ; 35(19)2024 Feb 22.
Artigo em Inglês | MEDLINE | ID: mdl-38241734

RESUMO

Fluorescence resonance energy transfer (FRET) was found strongly enhanced by plasmon resonance. In this work, Nanoporous Gold with small amount of residual silver was used to form nanoporous gold/organic molecular layer compound with PSS and PAH. The ratio of its specific gold and silver content is achieved by controlling the time of its dealloying. Layered films of polyelectrolyte multilayers were assembled between the donor-acceptor pairs and NPG films to control distance. The maximum of FRET enhancement of 80-fold on the fluorescence intensity between the donor-acceptor pairs (CFP-YFP) is observed at a distance of ∼10.5 nm from the NPG film. This Nanoporous Gold with small amount of residual silver not only enhanced FRET 4-fold more than nanoporous gold of only gold content almost, but also effectively realized the regulation of FRET enhancement. The ability to precisely measure and regulate the enhancement of FRET enables the rational selection of plasmonic nanotransducer dimensions for the particular biosensing application.

3.
Nanomaterials (Basel) ; 12(9)2022 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-35564164

RESUMO

Surface-enhanced Raman scattering (SERS) technology can amplify the Raman signal due to excited localized surface plasmon (LSP) from SERS substrates, and the properties of the substrate play a decisive role for SERS sensing. Several methods have been developed to improve the performance of the substrate by surface modification. Here, we reported a surface modification method to construct carbon-coated nanoporous gold (C@NPG) SERS substrate. With surface carbon-assistant, the SERS ability of nanoporous gold (NPG) seriously improved, and the detection limit of the dye molecule (crystal violet) can reach 10-13 M. Additionally, the existence of carbon can avoid the deformation of the adsorbed molecule caused by direct contact with the NPG. The method that was used to improve the SERS ability of the NPG can be expanded to other metal structures, which is a convenient way to approach a high-performance SERS substrate.

4.
Nanomaterials (Basel) ; 13(1)2022 Dec 31.
Artigo em Inglês | MEDLINE | ID: mdl-36616097

RESUMO

Nanoporous metals possess excellent catalytic and optical properties that are related with surface morphology. Here, we modulated the ligament surface of nanoporous gold (NPG) by controlling electrochemical dealloying and obtained NPG with an improved enhancement of its surface-enhanced Raman scattering (SERS) property. We found that both high-density atomic steps and kinks on the curved surfaces and high-content silver atoms close to the ligament surface contributed to the high SERS ability. The presented strategy will be useful for the fabrication of nanoporous metal with an excellent surface that is needed for sensing, conversion, and catalytic.

5.
Inorg Chem ; 57(17): 10511-10517, 2018 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-30118221

RESUMO

Unexpected Sc/Ln codoped rare earth metal-organic frameworks (RE-MOFs) molecular alloys (MAs) based on an oxalic acid ligands were obtained. Calcination of the RE-MOFs MAs gave the corresponding codoped rare earth oxides a strong and nearly pure red color upconversion luminescence. It allows the resulting lanthanide ion (Ln3+) doped upconversion materials a wide range of applications from optical communications to disease diagnosis. Moreover, the pyrolysis RE-MOFs MAs precursor has demonstrated to be an effective preparation method for a uniform Ln-doped Sc2O3 system.

6.
Zhongguo Zhong Yao Za Zhi ; 34(16): 2031-3, 2009 Aug.
Artigo em Chinês | MEDLINE | ID: mdl-19938538

RESUMO

OBJECTIVE: Various treatments were used in packaging and storing dry and fresh Radix Astragali in order to explore an economically practical storage method. METHOD: The experiment was designed in single-factor completely random as compared with the traditional stacking without package in which the character, quality, polysaccharide and extract contents were measured. RESULT: If stored for long-term use, the Radix Astragali should be packaged with vacuum-exhausted bags after cleaning by water and dried, which resulted in less weight loss, higher extract and polysaccharide. However, if stored for fresh use, the fresh Radix Astragali should be packaged in vacuum-exhausted bags after cleaning by sorghum alcohol and stored under low temperatures if possible, which resulted in less loss and longer fresh time. Considering polysaccharide and extract content, it is better to use dried the Radix Astragali in storage. CONCLUSION: Before packaged in vacuum-exhausted bags, the dry Radix Astragali should be cleaned by water for long-term use and cleaned by sorghum alcohol for fresh use under low temperatures if possible.


Assuntos
Astrágalo/química , Tecnologia Farmacêutica/métodos , Embalagem de Medicamentos , Estabilidade de Medicamentos , Armazenamento de Medicamentos , Medicamentos de Ervas Chinesas/análise , Controle de Qualidade
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