Parallel dual-color fluorescence cross-correlation spectroscopy using diffractive optical elements

M. Gösch; H. Blom; S. Anderegg; K. Korn; P. Thyberg; M. Wells; T. Lasser; R. Rigler; A. Magnusson; Sverker Hård

doi:10.1117/1.2080707

Parallel dual-color fluorescence cross-correlation spectroscopy using diffractive optical elements
Journal article, 2005

Dual-color cross-correlation spectroscopy allows the detection and quantification of labeled biomolecules at ultra-low concentrations, whereby the sensitivity of the assay correlates with the measurement time. We now describe a parallel multifocal dual-color spectroscopic configuration employing multiple avalanche photodiodes and hardware correlators. Cross-correlation curves are obtained from several dual-color excitation foci simultaneously. Multifocal dual-color excitation is achieved by splitting each of two laser beams (488 and 633 nm) into four sub-beams with the help of two 2 × 2 fan-out diffractive optical elements (DOEs), and subsequent superposition of the two sets of four foci. The fluorescence emission from double-labeled biomolecules is detected by two 2 × 2 fiber arrays.