Insights on proximity effect and multiphoton induced luminescence from gold nanospheres in far field optical microscopy
Artikel i vetenskaplig tidskrift, 2015

Goldnanoparticles can be visualized in far-field multiphoton laser-scanning microscopy (MPM) based on the phenomena of multiphoton induced luminescence (MIL). This is of interest for biomedical applications, e.g., for cancer diagnostics, as MPM allows for working in the near-infrared(NIR) optical window of tissue. It is well known that the aggregation of particles causes a redshift of the plasmon resonance, but its implications for MIL applying far-field MPM should be further exploited. Here, we explore MIL from 10 nm goldnanospheres that are chemically deposited on glass substrates in controlled coverage gradients using MPM operating in NIR range. The substrates enable studies of MIL as a function of inter-particle distance and clustering. It was shown that MIL was only detected from areas on the substrates where the particle spacing was less than one particle diameter, or where the particles have aggregated. The results are interpreted in the context that the underlying physical phenomenon of MIL is a sequential two-photon absorption process, where the first event is driven by the plasmon resonance. It is evident that goldnanospheres in this size range have to be closely spaced or clustered to exhibit detectable MIL using far-field MPM operating in the NIR region.

Plasmons

Cluster analysis

Gold

Nanoparticles

Luminescence

Författare

Johan Borglin

Göteborgs universitet

Stina Guldbrand

Göteborgs universitet

Hanne Evenbratt

Chalmers, Kemi och kemiteknik, Tillämpad kemi, Farmaceutisk teknologi

Vladimir Kirejev

Göteborgs universitet

Henrik Grönbeck

Kompetenscentrum katalys (KCK)

Chalmers, Teknisk fysik, Kemisk fysik

Marica B Ericson

Göteborgs universitet

Applied Physics Letters

0003-6951 (ISSN) 1077-3118 (eISSN)

Vol. 107 23 artikel nr 234101- 234101

Ämneskategorier

Atom- och molekylfysik och optik

Styrkeområden

Materialvetenskap

DOI

10.1063/1.4936554