Ultrasonic enrichment of microspheres for ultrasensitive biomedical analysis in confocal laser-scanning fluorescence detection

: Wiklund M., Toivonen J., Tirri M., Hänninen P., Hertz H.

: 2004

Journal of Applied Physics

: 96

: 2

: 1242

: 1248

: 7

: 0021-8979

DOI: https://doi.org/10.1063/1.1763226

: http://api.elsevier.com/content/abstract/scopus_id:3242667289

Ultrasensitive biomedical analysis by concentration of biologically active microspheres was discussed. For the study, an ultrasonic particle concentrator (UPC) based on a standing-wave hemispherical resonator was combined with a confocal-laser scanning fluorescence detection. The UPC collects microspheres in plane, dense, single-layer aggregates at well-defined positions controlled by the acoustic resonator geometry and the acoustic frequency, far from the vessel boundary. It is suggested that two major factors that influence the sensitivity of a single-step homogeneous microsphere-based assay are the analyte-to-microsphere ratio and the concentration of microspheres in the sample.