Colorimetric Protein Sensing by Controlled Assembly of Gold Nanoparticles Functionalized with Synthetic Receptors
2009 (English)In: Small, ISSN 1613-6810, Vol. 5, no 21, 2445-2452 p.Article in journal (Refereed) Published
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 Zn2+-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 approximate to 10 nM and approximate to 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.
Place, publisher, year, edition, pages
2009. Vol. 5, no 21, 2445-2452 p.
bioassays, gold, helical structures, hybrid materials, nanoparticles
IdentifiersURN: urn:nbn:se:uu:diva-127413DOI: 10.1002/smll.200900530ISI: 000271791100015OAI: oai:DiVA.org:uu-127413DiVA: diva2:329858