Fluorescence imaging is a powerful technique with ever increasing importance in fields like microscopy and medical imaging. The new wealth of available fluorescent probes enable many new applications in chemistry and biology research, in drug discovery or medical diagnosis. Fluorescence lifetime imaging is an even more powerful technique that solves some of the shortcomings of fluorescence imaging and even adds extra information to the measurement. In lifetime imaging, the average time a fluorescent molecule spends in its excited state is measured and this lifetime can be used to identify and detect fluorescent probes or retrieve information about their surrounding on a nanometer scale. However, fluorescence lifetime imaging puts tough requirements on the instrumentation as the measured lifetimes are on the order of nanoseconds or even sub-nanosecond and this for very weak fluorescent light. Sensors are required that are both very efficient over a broad wavelength range and fast enough to resolve sub-nanosecond lifetimes, all the way from blue to near-infrared. In this work, novel CMOS sensors for gated detection of fluorescence lifetime are investigated and developed. The result is a pixel-size low-cost CMOS sensor that is capable of sub-nanosecond fluorescence lifetime detection over the full relevant wavelength range for fluorescence. A prototype device, housing this sensor, has been built with all necessary picosecond timing electronics and low-noise readout. This prototype is used for lifetime detection of solutions or imaging on a scanning microscope. Even more promising is the fact that this sensor can be used as pixels in an image sensor for use in a fluorescence lifetime camera. Such a break-through camera will enable fluorescence lifetime imaging at video-rates for imaging dynamic processes or fluorescence-guided surgery.
|Award date||27 Oct 2017|
|Place of Publication||Brussels|
|Publication status||Published - 2017|