ISSN:
1436-5073
Keywords:
Key words: metal nano-clusters; surface enhanced absorption; array; test-stick.
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
Notes:
Abstract Resonant enhancement of absorptive properties of metal clusters bound to a surface by biorecognitive interactions is an effective means to set up bio-optical devices. Resonant amplification of a four-layer system has been proposed and recently demonstrated with a metal mirror, a polymer distance layer, a biomolecule interaction layer and a sub-monolayer of biorecognitively bound metal nano-clusters. Calculations and corresponding experiments indicated a strong influence of cluster symmetry and cluster shell on the distinct reflection minimum induced by the resonant behavior. Here, we present the first biosensor which clearly shows a narrow reflection minima system in the red or infra-red and therefore far away from the limit exhibited by spherical gold colloids at around 600 nm. The asymmetry of the metal clusters (synthesized by thermal step reduction in a detergent system) as well as metal–dielectric shell clusters (synthesized by multiple shell deposition processes) enabled us to shift the readout of the device to a frequency range where blood is highly transparent. Disposable single step assays were established, employing lectin–sugar, antigen–antibody and protein–receptor interactions.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/s006040050015
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