Review on recent trends and prospects in π‐conjugated luminescent aggregates for biomedical applications

Abstract

Metal‐free organic molecules with structurally diverse aggregation‐induced emission (AIE) behavior and new functional photophysical properties reveal unique structure–property relationships, especially bright luminescence, and have attracted extensive attention in the past few decades. Despite tremendous progress on fluorescent molecules development, the extended π‐conjugated organic AIE probes with their nanorange self‐assembly, coassembly, unique morphology, high biocompatibility, and light‐harvesting capabilities enable them as potential candidates in numerous translational application perspectives. In particular, a few important classes of AIE light up small molecules, supramolecules, oligomers, polymers, including nanoparticles and photosensitizer molecules, with their emerging properties of thermally activated delayed fluorescence, room temperature phosphorescence, including emission switching stimuli‐responsive behavior and multifunctional properties, have been boosted by the rare features of aggregation at their condensed or solid states. This review highlights salient features of AIE‐based emitters, encompassing molecular design strategies, stimulating photophysical properties, mechanistic aspects, and their efficacy in various electronic and biomedical applications, broadly covering properties of small molecules to oligomers, macromolecules to polymers.

Exceptional class of thermally activated delayed fluorescent emitters that display pure blue, near-IR, circularly polarized luminescence and multifunctional behaviour for highly efficient and stable OLEDs

“…Moreover, the growth of TADF materials is still at the development phase and is far from the commercialization of TADF OLEDs for the marketplace; therefore, a complete understanding of the mechanism and theory, new molecular design strategies, and in-depth photophysical studies of TADF emitters for many suitable applications remains attractive. Notably, among the probable potential applications of TADF materials, extension to newer research areas, such as biomedical applications [91][92][93] and photo-catalysis, 94,95 have seen decent progress. Therefore, having a clear vision of the different types of TADF material and their properties will inspire researchers to extend these TADF materials to other new translational applications.…”

Origin of luminescence properties and synthetic methods for gold- and bimetallic gold-based nanomaterials

“…2B). 104 Aiken's group provided theoretical insights into the origin of luminescence in Ag 25 (SR) 18 À NCs. 110 111 The Au 13 core of the NCs is mainly associated with UV-vis absorption.…”

“…3.1.1.1 Amino acid-stabilized AuNCs. Au 25 (Cys) 18 NCs were synthesized via a simple one-pot method in the presence of L-Cys as a stabilizing agent. This methodology enabled the sizecontrolled synthesis of Au 25 (SR) 18 NCs on a large scale using CO as a reducing agent.…”

“…Au 25 (Cys) 18 NCs were synthesized via a simple one-pot method in the presence of L-Cys as a stabilizing agent. This methodology enabled the sizecontrolled synthesis of Au 25 (SR) 18 NCs on a large scale using CO as a reducing agent. 173 Different stages of the growth and formation of Au 10-15 NCs (20 min), Au 10-15 to Au 16-25 NCs (20-90 min), and Au 16-25 to Au 25 NCs were finally illustrated using UV-Visible spectroscopy and MALDI-TOF analysis.…”

“…The advantages and disadvantages of organic fluorophores vs. metal-based nanoclusters are summarized in Table 1. [15][16][17][18] Hence, recently, review articles and perspectives on metal-based nanomaterials have attracted significant attention for a wide range of applications. [19][20][21][22][23][24][25][26][27][28] Among the applications of metalbased NPs, hypoxic tumor radiotherapy is one of the most important for clinical cancer treatment.…”