Institute of Polymer Science and Engineering, National Taiwan University, Taipei 10617, Taiwan.
Biomacromolecules. 2024 Sep 9;25(9):5758-5770. doi: 10.1021/acs.biomac.4c00289. Epub 2024 Aug 15.
Lanthanide-containing luminescent hydrogels have shown potential for sensing and imaging applications. Nonetheless, integrating lanthanide ions or complexes into the polymer matrix often results in the poor stability and mechanical strength of the hydrogels. This work presents an innovative approach to fabricating luminescent hydrogels with three dynamic cross-links: imine bond, boronate ester bond, and metal-ligand coordination. Europium(III) (Eu) ions are incorporated into a dual-cross-linked matrix composed of phenylboronic acid-polyethylenimine-modified gelatin (PPG) and alginate dialdehyde (ADA) through a combined treatment involving freeze-drying-swelling (FDS) and freeze-thawing (FT) processes. The FDS process facilitates the formation of additional europium-carboxylate cross-links within the polymeric network to enhance its luminescence and stability, while the FT process strengthens the network physically. The impact of the FDS-FT cycle number on the microstructures and properties of PPG/ADA-Eu hydrogels is thoroughly investigated, and their potential for monitoring bacterial growth and detecting copper(II) ions is also demonstrated.
含镧系元素的发光水凝胶在传感和成像应用方面显示出了潜力。然而，将镧系离子或配合物整合到聚合物基质中通常会导致水凝胶的稳定性和机械强度较差。本工作提出了一种将三种动态交联键：亚胺键、硼酸酯键和金属-配体配位键整合到发光水凝胶中的创新方法。通过涉及冻干-溶胀（FDS）和冻融（FT）过程的联合处理，将铕（III）（Eu）离子掺入由苯硼酸-聚乙烯亚胺修饰明胶（PPG）和海藻酸钠二醛（ADA）组成的双交联基质中。FDS 过程有助于在聚合物网络内形成额外的铕-羧酸交联以增强其发光和稳定性，而 FT 过程则从物理上增强网络。详细研究了 FDS-FT 循环次数对 PPG/ADA-Eu 水凝胶的微观结构和性能的影响，并证明了它们在监测细菌生长和检测铜（II）离子方面的潜力。
