Portably and Visually Sensing Cytisine through Smartphone Scanning Based on a Post‐Modified Luminescence Center Strategy in Zinc‐Organic Frameworks

Abstract

Cytisine (CTS) is a useful medicine for treating nervous disorders and smoking addiction, and exploring a convenient method to detect CTS is of great significance for long‐term/home medication to avoid the risk of poisoning, but it is full of challenges. Here, a modified metal‐organic framework sensor Tb@Zn‐TDA‐80 with dual emission centers was prepared using a post‐modified luminescence center strategy. The obtained Tb@Zn‐TDA‐80 can serve as a CTS sensor with high sensitivity and selectivity. To achieve portable detection, Tb@Zn‐TDA‐80 was further fabricated as a membrane sensor, M‐Tb@Zn‐TDA‐80, which displayed an obvious CTS‐responsive color change by simply dropping a CTS solution onto its surface. Benefiting from this unique functionality, M‐Tb@Zn‐TDA‐80 successfully realized the visual detection and quantitative monitoring of CTS in the range of 5.26‐52.6 mM by simply scanning the color with a smartphone. The results of nuclear magnetic resonance spectroscopy and theoretical computation illustrated that the high sensing efficiency of Tb@Zn‐TDA‐80 for CTS was attributed to the N‐H⋅⋅⋅π and π⋅⋅⋅π interactions between the ligand and CTS. And luminescence quenching may result from the intramolecular charge transfer. This study provides a convenient method for ensuring long‐term medication safety at home.