An ultrasensitive 4-(Diethylamino) salicylaldehyd-based fluorescence enhancement probe for the detection of Al3+ in aqueous solutions and its application in cells

• Published in: Journal of photochemistry and photobiology. A, Chemistry. Chemistry., 2022-06, Vol.428, p.113854, Article 113854
• Main Authors: Lei, Xiaolan, Zou, Yingyi, Liang, Qingjian, Xu, Weishao, Lao, Shanshan, Yang, Bin, Li, Ligui, Yang, Liting, Liu, Hong, Ma, Li-Jun
• Format: Article
• Language: English
• Subjects: Al3; Fluorescence enhancement probe; Fluorescence test paper; Photoinduced electron transfer
• ISSN: 1010-6030; 1873-2666
• DOI: 10.1016/j.jphotochem.2022.113854

A salicylaldehyde-containing Schiff base has been used as fluorescent probe that can visually recognize low-concentration Al3+ fluorescence changes in aqueous solutions and in cells. [Display omitted] •Probe L has a high selectivity and a fast response time.•Probe L has strong good photostability and anti-ion interference ability.•Probe L can detect low levels of Al3+ by the change of fluorescence color.•Probe L shows good potential as a fluorescent visualizing probe for Al3+ in cells.•Probe L can be made into fluorescent test paper. A fluorescence enhancement probe (L) with a high selectivity and sensitivity for the detection of Al3+ through photoinduced electron transfer (PET) mechanism was synthesized. In aqueous solution, L shows weak fluorescence emission due to the PET of the lone pair electron of the nitrogen atom on Schiff base group to the fluorophores. When Al3+ was added in the L solution, the coordination of Al3+ by the Schiff base group inhibited the PET process, resulting in significant enhancement of fluorescence, e.g. a factor of 20.6 at 5.0 μM. However, the addition of other common cations cannot induce such fluorescence enhancement response. Job’s plot and fluorescence spectra show a complexes of L-Al3+ with a 1:1 stoichiometry and a detection limit of 3.7 × 10−9 M−1. Furthermore, the binding model of L-Al3+ was further clarified by using NMR and density functional theory (DFT) calculations. L shows a fast response time, good photostability, wide measured range of pH and high repeatability. In addition, low levels of Al3+ (50.0 nM, i.e. 1.35 ppb) can render the fluorescence color of the probe solution from colorless to blue, offering a rapid and convenient method for the detection of trace Al3+. Based on the above results, a fluorescence test paper for the detection of Al3+ and a fluorescence visualizing method for the detection of Al3+ in living GS cells of epinephelus coioides were developed.