Recognition and determination of multi-metal ions based on silver nanoclusters capped by polyethyleneimine with different molecular weights

2015 ◽  
Vol 39 (12) ◽  
pp. 9293-9298 ◽  
Author(s):  
Fei Qu ◽  
Qianqian Zhang ◽  
Jinmao You
Keyword(s):  
Metal Ions ◽  
Silver Nanoclusters ◽  
Molecular Weights ◽  
Masking Agents ◽  
Ag Nanoclusters

Utilizing suitable masking agents, the fluorescence of Ag nanoclusters, quenched from adding Hg2+, Cu2+, Co2+, and Ni2+, could be restored.

Rapid determination of vitamin B12 (cobalamin) based on silver nanoclusters capped by polyethyleneimine with different molecular weights and terminal groups

2016 ◽  
Vol 8 (22) ◽  
pp. 4324-4327 ◽  
Author(s):  
Fei Qu ◽  
Qianwei Song ◽  
Jinmao You
Keyword(s):  
Vitamin B12 ◽  
Rapid Determination ◽  
Inner Filter Effect ◽  
Silver Nanoclusters ◽  
Vitamin B ◽  
Molecular Weights ◽  
Filter Effect

Ag nanocluster fluorescence can be dramatically quenched by vitamin B12 by the inner filter effect.

Glutathione-protected silver nanoclusters for sensing trace-level Hg2+ in a wide pH range

2015 ◽  
Vol 7 (4) ◽  
pp. 1558-1562 ◽  
Author(s):  
Yaping Zhong ◽  
Chun Deng ◽  
Yu He ◽  
Yili Ge ◽  
Gongwu Song
Keyword(s):  
Fluorescence Method ◽  
Silver Nanoclusters ◽  
Trace Level ◽  
Wide Ph Range ◽  
Ag Nanoclusters ◽  
Ph Range

A fluorescence method for the determination of Hg2+ in a wide pH range and based on the Ag nanoclusters was established.

Transmission Electron Microscopy of Protein Macromolecules

1971 ◽  
Vol 29 ◽  
pp. 424-425
Author(s):  
Henry S. Slayter
Keyword(s):  
Biological Systems ◽  
Metal Vapor ◽  
Resolving Power ◽  
Electron Microscopic ◽  
Chemical Methods ◽  
Molecular Weights ◽  
The Past ◽  
Physical Chemical ◽  
Transmission Electron

Electron microscopic methods have been applied increasingly during the past fifteen years, to problems in structural molecular biology. Used in conjunction with physical chemical methods and/or Fourier methods of analysis, they constitute powerful tools for determining sizes, shapes and modes of aggregation of biopolymers with molecular weights greater than 50, 000. However, the application of the e.m. to the determination of very fine structure approaching the limit of instrumental resolving power in biological systems has not been productive, due to various difficulties such as the destructive effects of dehydration, damage to the specimen by the electron beam, and lack of adequate and specific contrast. One of the most satisfactory methods for contrasting individual macromolecules involves the deposition of heavy metal vapor upon the specimen. We have investigated this process, and present here what we believe to be the more important considerations for optimizing it. Results of the application of these methods to several biological systems including muscle proteins, fibrinogen, ribosomes and chromatin will be discussed.

Preparation of graft copolymers by the reaction of polymeric acyl chlorides with monohydroxy-terminated polymers: An introductory study

1988 ◽  
Vol 53 (8) ◽  
pp. 1735-1744 ◽  
Author(s):  
Jitka Horská ◽  
Jaroslav Stejskal ◽  
Pavel Kratochvíl ◽  
Aubrey D. Jenkins ◽  
Eugenia Tsartolia ◽  
...  
Keyword(s):  
Light Scattering ◽  
Chemical Composition ◽  
Statistical Model ◽  
Graft Copolymers ◽  
Coupling Reaction ◽  
Molecular Characteristics ◽  
Gel Formation ◽  
Acyl Chlorides ◽  
Molecular Weights

An attempt was made to prepare well-defined graft copolymers by the coupling reaction between acyl chloride groups located along the backbone chain and monohydroxy-terminated grafts prepared separately. The molecular weights and the parameters of heterogeneity in chemical composition of the products were determined by light scattering and osmometry. The determination of molecular characteristics revealed that the degree of grafting was low. The results therefore could not be confronted with a statistical model at this stage. The problems encountered in the synthesis, e.g., gel formation, and the data relating to the soluble products are discussed.

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