Recent Advances in Organofluoroprobes for Brain Imaging: Progress, Challenges, and Future Directions

The precise and early diagnosis of neurodegenerative diseases remains a major challenge because of their highly complex and multifactorial pathophysiology. However, in recent years, the potential of organofluoroprobesorganic molecules designed to function as fluorescent probes in bioimaginghas become increasingly prominent. These probes enable visualization of essential biomarkers, including amyloid-beta (Aβ), tau, reactive oxygen and nitrogen species (ROS/RNS), neurotransmitters, and abnormal metal ions, facilitating early detection and monitoring of diseases such as Alzheimer's and Parkinson's. This review focuses on small-molecule organofluoroprobes, which consist of curcumin-, boron-dipyrromethane (BODIPY)-, cyanine-, coumarin-, benzothiazole-, thiophene-, naphthalene-, oxazine-, and organometallic-based systems. We also address biomarker-activated probes, nanoengineered aggregation-induced emission (AIE) luminogens, and photoacoustic probes that provide greater tissue penetration and multimodal imaging. Nevertheless, these imaging probes still have shortcomings, including poor specificity, limited penetration through the blood-brain barrier (BBB), and inefficient near-infrared II (NIR-II) emission. Notably, the design and optimization of fluoroprobes are being revolutionized by the integration of artificial intelligence (AI) and computational methods, such as deep learning, generative models, and virtual screening. These approaches provide new avenues for predictive modeling of physicochemical properties, target affinity and in vivo performance, thereby significantly reducing the time and cost of development. The review concludes by discussing current challenges and future perspectives, including the convergence of AI-assisted molecular design and synthetic chemistry in bioimaging, ultimately leading to the clinical translation of next-generation brain imaging probes.