Surfactant-mediated morphology and fluorescent properties of amino acids-based lanthanide coordination polymers

In this study, the effects of surfactants with different characteristics on the morphology and fluorescent properties of biomolecule-based lanthanide coordination polymers were investigated using Phe/Tb CPs (Phe = phenylalanine) as a model. In the presence of surfactants, significant changes in the morphologies of Phe/Tb CP can be observed, which are highly dependent on the charged characteristics and alkyl chain length of the surfactants. Compared with the anionic SDS, CTAB carrying positive charge and PVP with a super-long alkyl chain are favorable for the formation of monodispersed Phe/Tb CPs that are smaller in size and more uniform. This is due to the fact that the binding ability and steric effect of SDS to growing Phe/Tb are weaker than that of CTAB and PVP. Moreover, a significant increase in the fluorescent intensity and emission lifetime of Phe/Tb CPs were also found after the addition of surfactants, which indicate the influence of surfactants on the fluorescent properties of Phe/Tb CPs. We believe that the present study may be helpful for the rational design and preparation of functional fluorescent biomolecule-based LnCPs for biomedical applications.