Introduction to the Special Issue on Fluorescence Lifetime Imaging Microscopy (FLIM)
Fluorescence Lifetime Imaging Microscopy (FLIM) is an advanced tool that enables the description of exponential decay rate distribution of fluorescent molecules in the samples. This technique has been broadly used in biomedicine, material science, chemistry, and other related research fields, due to its ability to illustrate both localization of specific fluorophores and fluorophores’ local microenvironment, and it is superior to fluorescence intensity based imaging. However, the FLIM imaging speed is inherently limited due to the long exponential decay collecting process, which may not be proper for monitoring fast dynamic biological processes in tissue, not to mention at single protein level. Excellent fluorescence labeling techniques, advanced imaging techniques and efficient analytical tools together enable faster FLIM imaging. As the application of FLIM in biological field progresses, new requirements for FLIM technique are proposed, such as protein–protein interaction, label-free detection, deep tissue imaging, and so on.
In this Special Issue, four review papers and five original research articles are presented. For example, Liu et al. reviewed the recent progress on fast FLIM technique from the following aspects: the biophysical and electronic characteristics limiting FLIM speed, different imaging techniques for breaking the “speed limit” and different analytical tools for fast imaging.1 Wang et al. comprehensively introduced the FRET-FLIM technology including the principle, detection method and data processing, which enables the study of dynamic protein–protein interactions in biological field.2 Liu et al. and Li et al. reviewed the progress of FLIM-based skin cancer diagnosis3 and the application of TP-FLIM in tumor detection,4 respectively. In addition, five original studies presented in this issue range from FLIM-based cell death monitoring,5 excellent fluorescent probes (QDs and 3P dye) for FLIM,6,7 laser source for FLIM,8 to label-free FLIM-based tumor diagnosis.9 Overall, they present not only the FLIM technology itself, but also the application of FLIM in biological and biomedical fields, especially in protein–protein interactions and cancer diagnosis. Therefore, we strongly recommend this FLIM issue.
Junle Qu is a professor at the Center for Biomedical Photonics & College of Physics and Optoelectronic Engineering, Shenzhen University, China. His research interests include multimodal nonlinear optical imaging, super-resolution optical imaging, optical therapy, nanobiophotonics technologies for bio-sensing, imaging and therapy. He has published over 230 papers in peer-reviewed journals including Nature Photonics, Nature Communications, Chem, Chemical Society Reviews, Advanced Materials, Nano Letters, Optics Letters, Optics Express. He is a Fellow of SPIE and the director of Biomedical Photonics Committee of Chinese Optical Society. He serves on the editorial boards of several journals including Journal of Innovative Optical Health Sciences, Frontiers of Optoelectronics, etc.
Liwei Liu is a professor at Shenzhen University, China. She was a recipient of the Outstanding Youth Science Fund of the National Natural Science Foundation of China. She is the deputy secretary general of the Biomedical Photonics Branch of the Chinese Biomedical Engineering Society and a member of the editorial board of China Optics. She received her Ph.D. from Changchun University of Science and Technology in 2013. She visited the State University of New York at Buffalo as an academic exchange student from March 2010 to March 2011, and from November 2011 to May 2012. Her research direction is biomedical photonics, mainly focusing on nonlinear optical imaging and fluorescence lifetime microscopic imaging research. In the past five years, she has published more than 70 papers in domestic and international journals. She has obtained three authorized invention patents and won two provincial/ministerial level awards.
