Fluorophores with Imidazole Building Blocks and Their Multifunctional Platforms for Optoelectronics (LEDs/OLEDs), Chemo-Sensing, and Security Applications: Recent Advances and Future Perspectives

Abstract

Organic fluorophores featuring imidazole-based donor-π-acceptor (D-π-A) architectures have received significant attention due to their exceptional photophysical characteristics, such as strong emission, structural tunability, and environmental responsiveness. This review provides a comprehensive literature review on developing imidazole-containing D-π-A fluorophores, highlighting their structural diversity and functional adaptability. The article outlines the role of molecular engineering in tuning charge transfer processes and achieving desirable optical properties, including locally excited (LE), charge transfer (CT), and hybridized local and charge transfer (HLCT) states. Incorporating imidazole units has proven effective in improving thermal stability, electronic communication, and emission color control, especially in designing materials for organic light-emitting diodes (OLEDs) and hybrid white LEDs. Recent reports on imidazole-based picric acid and pH sensing systems have also been critically reviewed. The literature also demonstrates the potential of these materials in forensic science through their application in latent fingerprint visualization. This article also thoroughly discusses the design strategies of imidazole-based D-π-A fluorophores for versatile applications.