Fluorescence microscopic visualization of functionalized hydrogels

Abstract Functionalized hydrogels play an important part in chemistry, biology, and material science due to their unique microstructures. Characterization of these microstructures is the fundamental issue to improve the optical, mechanical, and biochemical performance of functionalized hydrogels. With the rapid development of fluorescence microscopy, a growing number of researchers have attempted to utilize this easily operated, noninvasive, and high-contrast technique to visualize the fine microstructure of hydrogels. Integration of a confocal system into fluorescence microscopy allows the sectioning and reconstruction of 3D hydrogel networks. The live recording function offers in situ and real-time images of dynamic behaviors within hydrogels. The development of super-resolution fluorescence microscopy has significantly promoted imaging quality from the submicron scale to the nanoscale. Based on these spectacular achievements, we reviewed the recent advances in fluorescence microscopic visualization of internal morphologies, mechanical properties, and dynamic structural changes. The scope of this review is to provide inspiration for researchers in chemistry, material science, and biology to study and fabricate functionalized hydrogels with the assistance of fluorescence microscopic visualization.