Fluorescence lifetime of dye molecules is a sensitive reporter on local microenvironment which is generally independent of fluorophores concentration and can be used as a means of discrimination between molecules with spectrally overlapping emission. It is therefore a potentially powerful multiplexed detection modality in biosensing but requires extremely low light level operation typical of biological analyte concentrations, long data acquisition periods and on-chip processing capability to realize these advantages. We report here fluorescence lifetime data obtained using a CMOS-SPAD imager in conjunction with DNA microarrays and TIRF excitation geometry. This enables acquisition of single photon arrival time histograms for a 320 pixel FLIM map within less than 26 seconds exposure time. From this, we resolve distinct lifetime signatures corresponding to dye-labelled HCV and quantum-dot-labelled HCMV nucleic acid targets at concentrations as low as 10 nM.
- fluorescence microscopy
- lifetime-based sensing
- medical optics instrumentation
- biological sensing and sensors
- avalanche photodiodes
Giraud, G., Schulze, H., Li, D-U., Bachmann, T. T., Crain, J., Tyndall, D., Richardson, J., Walker, R., Stoppa, D., Charbon, E., Henderson, R., & Arlt, J. (2010). Fluorescence lifetime biosensing with DNA microarrays and a CMOS-SPAD imager. Biomedical Optics Express, 1302-1308. https://doi.org/10.1364/BOE.1.001302