Modulation of redox reactivity of resazurin through host-guest complexation with Cucurbit[]uril ( = 7, 8).

Resazurin (Alamar Blue, RZ) is a widely utilized fluorescent probe for biological sensing, whose fluorescent intensity can be modulated by changing its redox states; thereby, electrochemical reactivity of RZ is of significance when designing a sensing assay. Herein, we report novel two-way electrochemical reactivity modulation of RZ using host-guest complexation with rigid molecular containers cucurbit[]uril (CB, = 7, 8). The complexation between CB and RZ is confirmed by H NMR measurements and supported by computational simulation, and the binding constants are determined via UV-vis titration.