Small-Molecule Fluorescent Probes for Visualizing Biological Processes: Nanoarchitectonics from Molecular Imaging to Clinical Theranostics

In recent years, molecular imaging techniques, particularly fluorescence imaging and photoacoustic imaging, have attracted increasing attention owing to their noninvasive nature, high sensitivity, and capability for real-time monitoring. Among various imaging agents, small-molecule fluorescent probes have emerged as powerful tools due to their high sensitivity, structural versatility, and compatibility with multiple imaging modalities. This review summarizes recent advances in the application of small-molecule fluorescent probes for molecular imaging, focusing on probe design strategies and imaging approaches targeting biomolecules, molecular events, and subcellular microenvironments. We further highlight their potential in disease diagnosis, fluorescence-guided surgery, and pharmacological evaluation. Overall, this review provides an overview of the unique advantages and broad applications of small-molecule fluorescent probes and discusses their prospects for precision medicine.