A hydroxyquinoline-base nanoprobe for fluorescent sensing of Hg 2+ ion in aqueous solution

Abstract

Abstract A new amphiphilic probe Q-16 bearing a hydroxylquinoline ring and a long hydrophobic cetyl chain has been synthesized and characterized. In aqueous solution, this probe can self-assemble fluorescent nano-structure aggregation, which is confirmed by the tyndall scattering experiment, dynamic light scattering (DLS) and transmission electron microscopy (TEM) techniques. Upon the addition of Hg 2+ , this probe shows a fluorescence quenching effect without interference from other metal ions. The detection limit of Q-16 to Hg 2+ is 4.42 nM. 1 H NMR titrations and DFT calculation results reveal that the triazole ring, the quinoline ring and the ether O atom of Q-16 play an important role for binding with the Hg 2+ center. However, probe Q-16 shows sensing of Hg 2+ , Cd 2+ , Ni 2+ , Cu 2+ and Al 3+ in CH 3 CN solution. Importantly, sensitivity and selectivity of Q-16 toward Hg 2+ in aqueous solution is higher than that in CH 3 CN solution for aggregation.