Phase-sensitive multichannel detection system for chemical and biosensor arrays and fluorescence lifetime-based imaging

Fluorescence lifetime-based sensors are attractive candidates to satisfy th e demand for chemical detection and monitoring in medical, pharmaceutical, and environmental applications. In many cases it is desirable not only to m onitor one particular chemical or biological species, but several simultane ously. In this work, we have focused our efforts on the development of a de tection platform for multianalyte sensor arrays that is able to monitor cha nges in the fluorescence lifetimes corresponding to the presence of many an alytes of interest in real time. We describe a new version of the multichan nel, phase-sensitive electronic detection system employing a multianode pho tomultiplier tube, light emitting diodes, laser diodes, custom-built detect ion electronics, and a software package. This system utilizes the frequency -domain method of time-resolved spectroscopy. The present 16-channel protot ype of the device is compact and assembled from inexpensive, off-shelf comp onents. Future detection systems may be expected to monitor simultaneously at least up to 63 signals from separate chemical and biosensors. The system is also suitable for lifetime-based imaging. The capabilities of this syst em are demonstrated with several examples, including a pH-sensitive sensor array measurement and lifetime-based imaging of spatially distributed chemi cal reactions. (C) 2000 American Institute of Physics. [S0034-6748(00)03102 -6].