Synthesis of a super-low detection limit fluorescent probe for Al3+ and its application in fluorescence imaging of zebrafish and cells

Abstract

A novel fluorescent probe N'-(2-hydroxybenzylidene)-indole-3-formylhydrazine (JHK) was designed and synthesized based on the condensation reaction of indole-3-formylhydrazine and salicylaldehyde. The probe JHK solution could highly selectively recognize Al³⁺ by the obvious fluorescence enhancement (288-fold) after adding Al³⁺. And the probe solution with Al³⁺ had a very high fluorescence quantum yield (89.29 %). The detection limit was calculated to be 1.135 nM, which was significantly lower than many reported detection limits, indicating that the probe JHK had pretty good sensitivity. The ratio of JHK to Al³⁺ (1:1) and the sensing mechanism were determined by Job's plot, ¹H NMR spectra, FTIR spectra, ESI-MS and Gaussian calculation. The probe solution and medium-speed filter paper were successfully used to make test papers for more convenient detection of Al³⁺. Furthermore, the probe JHK had been successfully applied to the detection of Al³⁺ in real water, zebrafish and living cells.

Keywords: Al(3+) detection; Fluorescent probe; Living cells; Low detection limit; Test papers; Zebrafish.