An Activatable NIR Yb4Zn2 Cluster for the Detection of Quercetin: Analysis of Host–Guest Interaction and Sensing Mechanism

A rod-like Yb4Zn2 nanocluster was constructed, which could be an activatable NIR probe for quercetin, with a short response time (5 s) and a low detection limit (0.75 μM). Theoretical simulations reveal that strong π···π interactions and hydrogen bonding result in good orbital overlap for charge transfer from quercetin to the cluster.