Affiliations: Macquarie University, North Ryde, NSW, Australia | Australian Proteome Analysis Facility Ltd &
Department of Chemistry and Biomolecular Science, Macquarie University, Sydney,
NSW, Australia
Note: [] Address for correspondence: Fang Xie, Department of Physics,
Division of Information and Communication Sciences, Macquarie University, North
Ryde, NSW 2109, Australia. Tel.: +61 2 68506598; Fax: +61 2 98508115; E-mail:
[email protected]
Abstract: We report here the first observation of appreciable enhancement of
fluorescence induced by large Au colloids. Au monolayers with Au colloids of
40 nm, 59 nm, and 81 nm in radii, were formed on silane modified glass
surfaces, respectively. The nanoparticle densities were varied by varying the
deposition times and documented by scanning electron microscopy. Two types of
samples were prepared, with large inter-particle distance and hence little or
no inter-particle coupling and small inter-particle distance with
inter-particle coupling. The fluorescence enhancement was examined by using a
self assembled monolayer of the fluorophore-protein conjugate with Deep Purple
as a fluorophore and Bovine Serum Albumin as protein (DP-BSA). The data show
the over 15 fold enhancement under optimized conditions and reveal strong
variations with both inter-particle distance and particle size. Nanostructures
of appropriate size with optimized inter-particle distance thus prepared can
produce promising substrates for decent fluorescence enhancement. We
demonstrated that the Au colloid monolayers on glass surfaces are promising
substrates for fluorescence enhancement with outstanding macroscopic
homogeneity. This important feature will pave the way for the application of
our substrates in biotechnology and life sciences such as imaging and sensing
of biomolecules in proteomics.
