Visible-light Emission and Guidance in Adenine Crystals

Luminescence in biomolecules remains a vibrant frontier captivating researchers worldwide, yet nucleobases like adenine linger as underexplored gems. In this study, we unveiled adenine's outstanding emissive potential: protonation triggers green fluorescence (≈ 500 nm) in solution, while its crystals show intense blue emission (412 nm) with high quantum yield (66%) under 365 nm ultraviolet irradiation. Corroborated by crystallographic analysis and controlled experiments, a decent understanding of underlying mechanisms is proposed. Furthermore, the potential optical waveguiding capabilities of adenine crystals were investigated, revealing excellent performance.