Au nanoparticles prepared by physical method on Si and sapphire substrates for biosensor applications

J. Spadavecchia, P. Prete, N. Lovergine, L. Tapfer, R. Rella

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Abstract

Gold nanoparticles heavily functionalized with oligonucleotides have been used in a variety of DNA detection methods. The optical properties of three-dimensional aggregates of Au nanoparticles in solution or deposited onto suitable surfaces have been analyzed to detect hybridization processes of specific DNA sequences as possible alternatives to fluorescent labeling methods. This paper reports on the preparation of gold nanoparticles directly deposited onto the surface of silicon (Si) and sapphire (Al2O3) substrates by a physical methodology, consisting in the thermal evaporation of a thin Au film and its successive annealing. The method guarantees the preparation of monodispersed single-crystal Au nanoparticles with a strong surface plasmon resonance (SPR) peak centered at about 540 nm. We show that the changes of SPR excitation before and after DNA functionalization and subsequent hybridization of Au nanoparticles immobilized onto Si and Al2O 3 substrates can be exploited to fabricate specific biosensors devices in solid phase. © 2005 American Chemical Society.
Original languageEnglish
Pages (from-to)17347 - 17349
Number of pages3
JournalJournal of Physical Chemistry B
Volume109
Issue number37
DOIs
Publication statusPublished - 22 Sep 2005
Externally publishedYes

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All Science Journal Classification (ASJC) codes

  • Physical and Theoretical Chemistry

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