Efficient and White-Light-Like Emission from Nonconventional Luminescent Materials in Solution States

Nonconventional luminescent materials (NLMs) offer promising alternatives to traditional organic luminophores owing to their lack of extensive π-conjugated structures. These materials offer inherent advantages like good biocompatibility, hydrophilicity, low cytotoxicity, and environmental friendliness, along with simple synthesis methods. However, achieving efficient luminescence in NLMs often necessitates highly concentrated solutions or solid states, which can be detrimental to cells due to cytotoxicity and osmotic pressure changes, hindering their potential in bioimaging. This work presents the synthesis of three polyesters, HJ-1, HJ-2, and HJ-3, via a ring-opening reaction of diglycidyl 1,2-cyclohexanedicarboxylate with enamines. These polymers exhibit remarkable concentration- and excitation wavelength-dependent fluorescence emission in dilute solutions, achieving a maximum quantum yield of 8.8% at 0.1 mg/mL. Notably, HJ-3 displays a rare white-like emission in solution. Additionally, these NLMs demonstrate sensitivity to temperature and pH variations, making them promising fluorescent probes. Their low cytotoxicity, good biocompatibility, and efficient low-concentration luminescence highlight their potential as valuable tools for cell imaging applications.