Thermo-triggered release of a Cys probe from the cavity of a water-soluble pillar[5]arene

Abstract A novel [2]pseudorotaxane based on thermo-responsive water-soluble pillar[5]arene WP5 and Cys probe 1 was successfully prepared in water. This complex exhibited no responsiveness to Cys at room temperature due to its high stability that inhibited the interaction between probe 1 and Cys. However, the encapsulated 1 could be released from the cavity of WP5 upon heating, leading to the formation of 1 –Cys adduct. Moreover, the probe could be used to monitor Cys with high sensitivity. Importantly, WP5 , 1 , and the [2]pseudorotaxane WP5 ⊃ 1 showed excellent biocompatibility, making the probe a very attractive candidate for biological applications.