An effective dual functional indole-based probe for sensing Ni²⁺ and Ce³⁺ ions respectively

A novel indole-based acylhydrazone derivative has been synthesized and characterized by the four spectrums (¹H and ¹³C NMR, IR, and HRMS). The configuration of acylhydrazone is confirmed to be E_C(O)NE_CN through X-ray diffraction. This probe demonstrates a bifunctional chemosensor for the detection of Ni²⁺ and Ce³⁺ via distinct optical responses, which exhibits an AIE fluorescence on response to Ce³⁺, LOD = 4.24 × 10^-7 M, and a fluorescence off response for Ni²⁺, LOD = 3.15 × 10^-7 M. Job's plot analysis confirms the formation of a 1:1 stoichiometric complex between the probe and Ni²⁺. Furthermore, the probe IPCA also demonstrates as a triple-mode sensor to Ni²⁺, enabling naked-eye colorimetric detection under natural light.