Time-resolved confocal scanning device for ultrasensitive fluorescence detection

A confocal laser-scanning microscope for ultrasensitive fluorescence lifeti me imaging on surfaces is presented. The system employs a compact electroni cs for time-correlated single-photon counting (TCSPC), allowing for measuri ng fluorescence lifetime with 40 ps time resolution, and for continuously r ecording photon arrival times with 100 ns time resolution. Additionally dev eloped driver electronics serve for synchronization of scanning and data ac quisition, which is significant for achieving high spatial image resolution . The capabilities of the measurement system are demonstrated on imaging si ngle molecules immobilized on glass substrates. Finally, it is shown how th e TCSPC capabilities of the system can be used not only for lifetime imagin g but also for multichannel measurements. (C) 2001 American Institute of Ph ysics.