A natural inspired amino acid-based biological pigment for near-infrared cell imaging

Biomimetic nanomaterials inspired by natural fluorescent molecules have been extensively applied in the biomedical field because of their unique fluorescence characteristics and biocompatibility. Nevertheless, the inherent complex molecular structure of many natural organisms and the unclear oxidation process pose limitations on their preparation and application. Consequently, the rational design of biomimetic alternative structures with exceptional performance remains a formidable challenge. Drawing inspiration from the synthesis pathway of natural betalains, here we designed a blue-violet biomimetic pigment named t-butyloxy carbonyl-L-Tyr-Ile pigment (BYIP). As a new class of β-acid derivatives, this artificially designed molecule has an extended π-conjugated system and can self-assemble into aggregated nanospheres with stable near-infrared fluorescence emission under simple enzymatic oxidation. By regulating its synthesis and assembly processes, the macroscopic color and fluorescence properties of this pigment can be directionally regulated, and its excellent biocompatibility and fluorescence stability contribute to further applications in the field of biological imaging. The design concept of this biomimetic pigment provides a promising approach for constructing fluorescent biological nanostructures suitable for biomedical applications. [Display omitted]