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Schofield, Claire L., Haines, Alan H., Field, Robert A. 
ORCID: https://orcid.org/0000-0001-8574-0275 and Russell, David A.
(2006)
Silver and gold glyconanoparticles for colorimetric bioassays.
Langmuir, 22 (15).
pp. 6707-6711.
ISSN 0743-7463
Abstract
The color changes associated with the aggregation of metal nanoparticles has led to the development of colorimetric-based assays for a variety of target species. We have examined both silver- and gold-based nanoparticles in order to establish whether either metal exhibits optimal characteristics for bioassay development. These silver and gold nanoparticles have been stabilized with a self-assembled monolayer of a mannose derivative (2-mercaptoethyl α-d-mannopyranoside) with the aim of inducing aggregation by exploiting the well-known interaction between mannose and the lectin Concanavalin A (Con A). Both metal glyconanoparticles were determined to be ca. 16 nm in diameter (using TEM measurements). Aggregation was observed on addition of Con A to both silver and gold nanoparticles resulting in a shift in the surface plasmon absorption band and a consequent color change of the solution, which was monitored using UV−visible spectrophotometry. Mannose-stabilized silver nanoparticles at a concentration of 3 nM provide an assay for Con A with the largest linear range (between 0.08 and 0.26 μM). Additionally, the kinetic rate of aggregation of the silver-nanoparticle-based bioassay was significantly greater than that of the gold-nanoparticle system. However, in terms of sensitivity, the mannose-stabilized gold-nanoparticle-based assay was optimum with a limit of detection of 0.04 μM Con A, as compared with a value of 0.1 μM obtained for the mannose-stabilized silver nanoparticles. Additionally, a lactose derivative (11-mercapto-3,6,9-trioxaundecyl β-D-lactoside) was used to stabilize gold nanoparticles to induce aggregation upon addition of the galactose specific lectin Ricinus communis agglutinin (RCA120). To examine the specificity of the bioassay, lactose-stabilized gold nanoparticles were mixed with a solution of mannose-stabilized silver nanoparticles to give an aggregation assay capable of detecting two different lectins. When either Con A or RCA120 was added to the mixed glyconanoparticles, selective recognition of the respective natural ligand was shown by aggregation of a single metal nanoparticle. Centrifugation and removal of the aggregated species enabled further bioassay measurements using the second glyconanoparticle system.
| Item Type: | Article |
|---|---|
| Faculty \ School: | Faculty of Science > School of Chemistry (former - to 2024) |
| UEA Research Groups: | Faculty of Science > Research Groups > Physical and Analytical Chemistry (former - to 2017) |
| Depositing User: | Users 2731 not found. |
| Date Deposited: | 28 Jan 2013 21:00 |
| Last Modified: | 24 Sep 2024 09:52 |
| URI: | https://ueaeprints.uea.ac.uk/id/eprint/41015 |
| DOI: | 10.1021/la060288r |
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