Abstract Summary/Description
Fluorescence imaging is a pivotal tool in modern biomedical research, offering non-invasive, real-time visualization of biological structures and processes with high resolution1. Among the various fluorophores, near-infrared (NIR) dyes are particularly valuable due to their deeper tissue penetration, reduced scattering, and minimal background autofluorescence2-4. In this study, we synthesized a class of squaraine fluorophores functionalized with primary and secondary amines, including amino acids, to investigate their optical and physicochemical properties. The incorporation of amino acids into the squaraine backbone not only enhances the biocompatibility of the dyes but also provides a specific targeting mechanism towards receptors that are overexpressed in tumor cells, enabling improved precision in tumor imaging5, 6. Additionally, the functionalization with amines and amino acids has been shown to improve the solubility of these dyes in aqueous environments, which is critical for their use in vivo. The modified squaraine NIR dyes will have improved optical properties for imaging applications.
