Colorimetric protein sensing by controlled assembly of gold nanoparticles functionalized with synthetic receptors.
Small
; 5(21): 2445-52, 2009 Nov.
Article
in En
| MEDLINE
| ID: mdl-19588465
ABSTRACT
A novel strategy is described for the colorimetric sensing of proteins, based on polypeptide-functionalized gold nanoparticles. Recognition is accomplished using a polypeptide sensor scaffold designed to specifically bind to the model analyte, human carbonic anhydrase II (HCAII). The extent of particle aggregation, induced by the Zn(2+)-triggered dimerization and folding of a second polypeptide also present on the surface of the gold nanoparticle, gives a readily detectable colorimetric shift that is dependent on the concentration of the target protein. In the absence of HCAII, particle aggregation results in a major redshift of the plasmon peak, whereas analyte binding prevented the formation of dense aggregates, significantly reducing the magnitude of the redshift. The versatility of the technique is demonstrated using a second model system based on the recognition of a peptide sequence from the tobacco mosaic virus coat protein (TMVP) by a recombinant antibody fragment (Fab57P). Concentrations down to approximately 10 nM and approximately 25 nM are detected for HCAII and Fab57P, respectively. This strategy is proposed as a generic platform for robust and specific protein analysis that can be further developed to monitor a wide range of target proteins.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Colorimetry
/
Metal Nanoparticles
/
Gold
Language:
En
Journal:
Small
Journal subject:
ENGENHARIA BIOMEDICA
Year:
2009
Document type:
Article
Affiliation country:
Sweden