Introduction to the Special Issue on Fluorescence Lifetime Imaging Microscopy (FLIM)

Abstract

Fluorescence Lifetime Imaging Microscopy (FLIM)is an advanced tool that enables the description of exponential decay rate distribution of°uorescent molecules in the samples. This technique has been broadly used in biomedicine, material science, chemistry, and other related research¯elds, due to its ability to illustrate both localization of speci¯c°u orophores and°uorophores' local microenvironment, and it is superior to°uorescence 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°uorescence labeling techniques, advanced imaging techniques and e±cient analytical tools together enable faster FLIM imaging. As the application of FLIM in biological¯eld 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 ve 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, di®erent imaging techniques for breaking the \speed limit" and di®erent 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 proteinprotein interactions in biological¯eld. 2 Liu et al. and Li et al. reviewed the progress of FLIM-based skin cancer diagnosis 3 and the application of TP-FLIM in tumor detection, 4 respectively. In addition, ve original studies presented in this issue range from FLIM-based cell death monitoring, 5 excellent°u orescent 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¯elds, especially in protein-protein interactions and cancer diagnosis. Therefore, we strongly recommend this FLIM issue.

Solvent‐Additive Engineering‐Assisted Improvement of Interface Contact for Producing Highly Efficient Inverted Perovskite Solar Cells

“…We collected the PL decay curves of each pixel in the FLIM images and fitted those using a single-exponential function. [46,47] The statistical histogram of PL lifetimes is shown in Figure 3c and the representative PL decay curves are shown in Figure 3d. The modified perovskite film displayed an average PL lifetime of 336 ns, much longer than that of the control perovskite film (average of 265 ns), indicating that a slower nonradiative recombination rate exists in the modified perovskite.…”