Fluorescence fluctuation spectroscopy is applied to study molecules passing through a small observation volume, usually subjected to diffusive or convective motion in a liquid phase. We suggest that such a technique could be used to measure the areal absolute concentration of fluorophores deposited on a substrate or embedded in a thin film, with a resolution of a few micrometers. The principle is to translate the solid substrate in front of a confocal fluorescence microscope objective and to record the subsequent fluctuations of the fluorescence intensity. The validity of this concept is investigated on model substrates (fluorescent microspheres) and DNA biochips.
© 2006 Optical Society of America
Original Manuscript: November 2, 2005
Revised Manuscript: January 17, 2006
Manuscript Accepted: January 17, 2006
Vol. 1, Iss. 5 Virtual Journal for Biomedical Optics
A. Delon, J. Derouard, G. Delapierre, and R. Jaffiol, "Measurement of surface concentration of fluorophores by fluorescence fluctuation spectroscopy," Opt. Lett. 31, 1142-1144 (2006)