A phenanthro[9,10-d]imidazole-based AIE active fluorescence probe for sequential detection of Ag+/AgNPs and SCN- in water and saliva samples and its application in living cells

摘要

Ag+ and SCN- play extremely important roles in the fields of the physiology and environment In this work, on the basis of phenanthro[9,10-d]imidazole derivative (DIPIP) which can exhibit the aggregation-induced emission (AIE) properties in aqueous solution, we achieved a sequential on-off-on switch for Ag+ and SCN- with high selectivity and sensitivity. A remarkable fluorescence quenching effect of Ag+ on the probe DIPIP was observed with 1:2 stoichiometry, Subsequently, the fluorescence intensity of in situ generated DIPIP-Ag+ ensemble was easily switched on after the interaction between Ag+ and SCN- which was attributed to the stronger affinity of SCN- to capture Ag+. In particular, the extreme limits of detection (LOD) for Ag+ and SCN- in standard solutions were as low as to be 74.5 nM and 7.8 nM, respectively. Furthermore, the probe DIPIP and the DIPIP-Ag+ ensemble could be used to detect Ag+ in the real water and SCN- in smoker saliva samples, respectively. In addition, the sequential "on-off-on" fluorescence mode of DIPIP to Ag+ and SCN- were also successfully applied in living HeLa cells. (C) 2019 Elsevier B.V. All rights reserved.