Convective-diffusion-based fluorescence correlation spectroscopy for detection of a trace amount of E. coli in water

De-Kui Qing; M Pinar Mengüç; Fred A Payne; Mary-Grace C Danao

doi:10.1364/ao.42.002987

Convective-diffusion-based fluorescence correlation spectroscopy for detection of a trace amount of E. coli in water

Appl Opt. 2003 Jun 1;42(16):2987-94. doi: 10.1364/ao.42.002987.

Authors

De-Kui Qing¹, M Pinar Mengüç, Fred A Payne, Mary-Grace C Danao

Affiliation

¹ Department of Mechanical Engineering, University of Kentucky, Lexington, Kentucky 40506-0108, USA.

PMID: 12790449
DOI: 10.1364/ao.42.002987

Abstract

Fluorescence correlation spectroscopy (FCS) is adapted for a new procedure to detect trace amounts of Escherichia coli in water. The present concept is based on convective diffusion rather than Brownian diffusion and employs confocal microscopy as in traditional FCS. With this system it is possible to detect concentrations as small as 1.5 x 10(5) E. coli per milliliter (2.5 x 10(-16) M). This concentration corresponds to an approximately 1.0-nM level of Rhodamine 6G dyes. A detailed analysis of the optical system is presented, and further improvements for the procedure are discussed.

Publication types

Research Support, Non-U.S. Gov't
Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

Escherichia coli / isolation & purification*
Models, Theoretical
Scattering, Radiation
Spectrometry, Fluorescence*
Water Microbiology*