A novel AIE active fluorescence chemosensor 1 is synthesized. 1 exhibits prominent selective and sensitivity detection of CN− in almost pure water. 1 achieves a low detection limited of 0.22 μm (9.44 ppm) towards CN−. 1 can be used to detect CN− in drinking water by test strips. 1 has potential for bioimaging in living cells with good cellular permeability and low cytotoxicity.