A label-free G-quadruplex and ThT mediated fluorescent sensor for detection of Cu2+ from water samples

• While living species require Cu 2+ , they are particularly sensitive to high levels of which can be toxic and even lethal. mostly reaches organisms via aquatic environments. Thioflavin T has the ability form a G-quadruplex complex with guanine rich DNA sequences where fluorescence intensity is produced as result this. High fluorescent by drops when binds . The fluorescent-changing mechanism was successfully used create rapid, label-free, sensor system against detection wide linear range 30.7 nM LOD. A facile label-free method based on formation structure sequence developed for rapid copper (Cu ) ion. many (G) repeats potential exhibits selectivity ThT promotes resulting in because its molecular rotor characteristic. As opposed to, target presence conformational changes occur, dissociation substantial decrease intensity. By virtue this change, unlabeled, low-cost, sensitive, selective achieved not interfered other ions. proposed sensitivity selectivity, limit nM, allowing it directly measure contaminated water samples from 0.1 100 µM recovery rate.