Institute of Materials Research and Engineering, Agency for Science, Technology, and Research (A*STAR), 2 Fusionopolis Way, Innovis, 138634, Singapore.
Institute of Materials Research and Engineering, Agency for Science, Technology, and Research (A*STAR), 2 Fusionopolis Way, Innovis, 138634, Singapore.
Int J Biol Macromol. 2021 Jan 1;166:869-875. doi: 10.1016/j.ijbiomac.2020.10.243. Epub 2020 Nov 2.
Luminescent hydrogels with sensing capabilities have attracted much interest in recent years, especially those responsive to stimuli, making such materials potential for various applications. Pectin is a high-molecular-weight carbohydrate polymer that has the ability to form hydrogel upon heating or mixing with divalent cations. However, intrinsic pectin gels are weak and lack of functionalities. In this study, lanthanide ions and silk fibroin derived carbon dots were incorporated into Pectin/PVA hydrogel (PPH) to form luminescent tough hydrogels. The luminescence of the hydrogel can be tuned by adjusting the ratio of blue emission carbon dots to Eu ions (red emission) and Tb ions (green emission). Such incorporation of emitters only slightly changed the mechanical properties of the tough hydrogel. Notably, the luminescent Pectin/PVA hydrogel (LPPH) showed chromic response to external stimuli, like pH and metal ions. By measuring the ratio of luminescent intensity at 473 nm and 617 nm (I/I), the pH response can be quantified in high sensitivity. In addition, the specific detection of Cu and Fe ions using the fabricated hydrogel were demonstrated, the mechanism was also proposed. The different chromic responses to Fe and Fe endow the luminescent tough Pectin/PVA hydrogel potential for multiple sensing applications.
近年来，具有传感功能的发光水凝胶引起了人们的极大兴趣，特别是那些对刺激有响应的水凝胶，使这类材料具有广泛的应用前景。果胶是一种高分子量的碳水化合物聚合物，具有在加热或与二价阳离子混合时形成水凝胶的能力。然而，天然果胶凝胶强度较弱且缺乏功能性。在本研究中，将镧系离子和丝素衍生的碳点掺入果胶/聚乙烯醇水凝胶（PPH）中，形成发光坚韧水凝胶。通过调节蓝色发射碳点与 Eu 离子（红色发射）和 Tb 离子（绿色发射）的比例，可以调节水凝胶的发光。这种发射体的掺入仅略微改变了坚韧水凝胶的力学性能。值得注意的是，发光果胶/聚乙烯醇水凝胶（LPPH）对外界刺激，如 pH 值和金属离子，表现出显色响应。通过测量 473nm 和 617nm 处发光强度的比值（I/I），可以定量检测高灵敏度的 pH 值响应。此外，还展示了使用所制备的水凝胶对 Cu 和 Fe 离子的特异性检测，同时提出了其作用机制。对 Fe 和 Fe 的不同显色响应使发光坚韧的果胶/聚乙烯醇水凝胶具有多种传感应用的潜力。
