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Lysine-functionalized silver nanoparticles for visual detection and separation of histidine and histidine-tagged proteins.
- Source :
-
Langmuir : the ACS journal of surfaces and colloids [Langmuir] 2010 Feb 02; Vol. 26 (3), pp. 2181-5. - Publication Year :
- 2010
-
Abstract
- A new chromogenic chemosensor based on lysine-functionalized silver nanoparticles 1 was prepared and characterized by transmission electron microscopy (TEM), Fourier transform Raman, and ultraviolet-visible (UV-vis) spectroscopy. The color changes of nanoparticles 1 in the absence and the presence of metal ion were observed upon addition of various amino acids and proteins in aqueous solution. Among the various amino acids, the sensor 1 in the absence of metal ion shows a novel colorimetric sensor with capability to probe histidine and histidine-tagged proteins. On the other hand, the color changes of 1 in the presence of metal ions such as KCl or NiCl(2) did not occur with any amino acids. Therefore, the sensor 1 in the absence of metal ion responds selectively to histidine, a response which can be attributed to its aggregation induced by histidine with high numbers of electrostatic interactions. This highly selective sensor 1 allows a rapid quantitative assay of histidine to concentrations as low as 5.0 microM, providing a new tool for the direct measurement of histidine and histidine-tagged proteins in vitro system. Furthermore, we examined the effect of pH on absorbance (A(520)) of 1 in the presence of histidine (pH 4-12). The absorbance under basic conditions was higher than that under acidic or neutral conditions, in accord with the stronger aggregation of 1 with histidine by electrostatic interaction between the carboxylate anion of 1 and ammonium protons of histidine under basic conditions.
- Subjects :
- Calorimetry
Histidine chemistry
Histidine metabolism
Ligands
Models, Molecular
Molecular Conformation
Proteins chemistry
Proteins metabolism
Spectrophotometry, Ultraviolet
Histidine analysis
Histidine isolation & purification
Lysine chemistry
Metal Nanoparticles chemistry
Proteins analysis
Proteins isolation & purification
Silver chemistry
Subjects
Details
- Language :
- English
- ISSN :
- 1520-5827
- Volume :
- 26
- Issue :
- 3
- Database :
- MEDLINE
- Journal :
- Langmuir : the ACS journal of surfaces and colloids
- Publication Type :
- Academic Journal
- Accession number :
- 19715339
- Full Text :
- https://doi.org/10.1021/la9026865