Jin Zhang,Shengzhen Hou,Yanru Chen,Jing Zhou,Hao Chen,Yebang Tan
The strategy of dual cross-linking was investigated by enhancing the performance of dynamic hydrogels. To this end, phenylalanine modified ε-polylysine was synthesized and employed as the polymer backbone of hydrogels. The phenylalanine moieties and amine groups of the polymer could be cross-linked with cucurbit[8]uril (CB[8]) and the dialdehyde cross-linker, respectively. Single CB[8] linkage with fast dynamics led to an increase in the viscosity of the polymer solution, and single imine linkage with slow dynamics led to the formation of weak and brittle hydrogels. However, the two linkages were combined together to form a dual-cross-linked hydrogel and the performance of the hydrogel could be well enhanced. Compared with the single imine cross-linked hydrogel, the dual-cross-linked hydrogel demonstrated a higher mechanical strength, better extensibility and faster self-healing rate. It is anticipated that this line of research could provide a useful method to enhance the performance of dynamic hydrogels.
Many fluorometric methods have been developed for detecting tyrosinase activity, yet many of them require the sophisticated synthesis of relatively complex fluorescent molecules. Here, we report the utilization of a label-free supramolecular tandem assay for measuring tyrosinase activity based on an easily available reporter pair. Cucurbit[8]uril (CB[8]) can bind with thioflavin-T (ThT) and increase its fluorescence intensity , while the tripeptides YLA and Dopa-LA can decrease the fluorescence intensity of CB[8]-ThT complex. YLA and Dopa-LA can be oxidized by tyrosinase, and the products have lower binding affinity with CB[8], leading to an increase of fluorescence in the intensity of CB[8]-ThT-YLA or Dopa-LA. We were able to continuously monitor tyrosinase activity with CB[8]-ThT-YLA or Dopa-LA.
危险品化学品经营许可证（带存储）