Gold Island Films: Properties and Applications in Localized Plasmon Biosensing

When: Wednesday, May 16, 2012 at 12:00 pm
Where: EG 406
Speaker: Professor Israel Rubinstein
Organization: The Weizmann Institute of Science
Sponsor: Special Seminar

Gold nano-island films prepared by evaporation on transparent substrates and annealing display a
localized surface plasmon resonance (LSPR) extinction, which is sensitive to the refractive index of
the adjacent medium. Such systems are of interest as optical transducers for label-free sensing using
simple, spectrophotometry-based detection systems.1 We have studied the preparation of random Au
island films on glass substrates with tunable morphology and optical properties using discontinuous
Au films as well as continuous films which undergo depercolation upon annealing.2,3 Such films show
exceptionally high refractive index sensitivity (RIS) values.3 High-temperature annealing induces
partial island embedding in the glass, thereby stabilizing the morphology and optical response.4
Biosensing applications of such transducers are demonstrated using biological systems showing
specific receptor–analyte interactions, including proteins,5 carbohydrates6 and RNA. Optimization of
the transducer performance requires matching of the RIS and plasmon decay length to the specific
analyte.7 The results indicate that LSPR transducers comprising random Au island films provide a
convenient, inexpensive and sensitive platform for studying biomolecular interactions and for labelfree
biosensing.

1 A. Vaskevich, I. Rubinstein, in Handbook of Biosensors and Biochips, R. Marks, D. Cullen, C. Lowe, H. H.
Weetall, I. Karube (Editors), Wiley, 2007, pp. 447-469.
2 T. Karakouz, D. Holder, M. Goomanovsky, A. Vaskevich, I. Rubinstein, Chem. Mater. 21, 2009, 5875-5885.
3 A. B. Tesler, L. Chuntonov, T. Karakouz, T. A. Bendikov, G. Haran, A. Vaskevich, I. Rubinstein, J. Phys.
Chem. C 115, 2011, 24642–24652.
4 T. Karakouz, A. B. Tesler, T. A. Bendikov, A. Vaskevich, I. Rubinstein, Adv. Mater. 20, 2008, 3893–3899.
5 T. A. Bendikov, A. Rabinkov, T. Karakouz, A. Vaskevich, I. Rubinstein, Anal. Chem. 80, 2008, 7487–7498.
6 G. Bellapadrona, A. B. Tesler, D. Grünstein, L. H. Hossain, R. Kikkeri, P. H. Seeberger, A. Vaskevich, I.
Rubinstein, Anal. Chem. 84, 2012, 232-240.
7 O. Kedem, A. B. Tesler, A. Vaskevich, I.R ubinstein, ACS Nano 5, 2011, 748-760.