A Fluorescent Probe for Al3+ Based on Calix[4]arene Containing Salicylaldehyde-Derived Schiff Base

Two novel fluorescent probes L1 and L2 for recognizing Al3+ have been prepared by cooperating salicylaldehyde-derived Schiff base groups onto the upper rim of the calix[4]arene. Of these probes, L2 is the most effective at recognizing Al3+, displaying a highly selective fluorescence "on" response with an emission wavelength at 478 nm and a Stokes shift of 88 nm. Additionally, probe L2 can form a 1: 1 coordination complex with Al3+ with a binding constant of 2.6x10(10) M-1. Furthermore, its fluorescence intensity exhibits a good linear relationship with Al3+ concentration within the range of 2.0x10(-5) M to 1.4x10(-4) M, and the probe has a low detection limit of 4.36x10(-7) M.