Activatable Near‐Infrared Versatile Fluorescent and Chemiluminescent Dyes Based on the Dicyanomethylene‐4H‐pyran Scaffold: From Design to Imaging and Theranostics

Abstract

Activatable fluorescent and chemiluminescent dyes with near‐infrared emission have indispensable roles in the field of bioimaging, molecular prodrugs, and phototheranostic agents. As one of the most popular fluorophore scaffolds, the dicyanomethylene‐4H‐pyran scaffold has been applied to fabricate a large number of versatile activatable optical dyes for analytes detection and diseases diagnosis and treatment by virtue of its high photostability, large Stokes shift, considerable two‐photon absorption cross‐section, and structural modifiability. This review mainly discusses the molecular design strategies, recognition mechanisms, and both in vitro and in vivo bio‐applications (especially for diagnosis and therapy of tumors) of activatable dicyanomethylene‐4H‐pyran dyes. The final section describes the current shortcomings and future development prospects of this topic.

Coordination Synergistic-Induced J-Aggregation Enhanced Fluorescent Performance of HBT-Excimers and Imaging Applications

“…Precisely and accurately obtaining endogenous biomolecular information to spy on the occurrence and development of diseases under external stress is greatly dependent on chemical tools, such as fluorescent probes. − Different masterly and subtle strategies have been adopted to fabricate novel smart probes with high optical performances to gain insights into biological events in physiological and pathological processes. , As one of the efficient strategies, J -aggregation plays a vital role in improving the emission wavelength of fluorophores, even to the second near-infrared window, which greatly helps reduce interferences from the background and elevate penetrable depth ability and imaging resolution. , However, after discovering the initial aggregate of the cyanine chloride, only several traditional skeletons of dyes were used for continual studying J -aggregation, such as porphyrins, perylene bisimides, phthalocyanines, and BODIPYs. , A limited number of J -aggregation-based fluorophore skeletons for imaging in living systems were available. In addition, a big problem with current available J -aggregation-based dyes is their instability due to weak intermolecular interactions.…”

“…1−3 Different masterly and subtle strategies have been adopted to fabricate novel smart probes with high optical performances to gain insights into biological events in physiological and pathological processes. 4,5 As one of the efficient strategies, J-aggregation plays a vital role in improving the emission wavelength of fluorophores, even to the second near-infrared window, which greatly helps reduce interferences from the background and elevate penetrable depth ability and imaging resolution. 6,7 However, after discovering the initial aggregate of the cyanine chloride, only several traditional skeletons of dyes were used for continual studying J-aggregation, such as porphyrins, perylene bisimides, phthalocyanines, and BODIPYs.…”