A tris-buffer appended Schiff base as a fluorescent probe for Al3+ and its potential application in Zebrafish imaging

Abstract

Aluminum (Al) levels in living organisms and the environment are vital to human health and the environment. Therefore, a rapid and susceptible probe for detecting Al³⁺ is required. A new fluorescent probe E)-2-(((8-hydroxy-2,3,6,7-tetrahydro-1H,5H-pyrido[3,2,1-ij]quinolin-9-yl)methylene)amino)-2-(hydroxymethyl)propane-1,3-diol (JulAmino-Tris), was developed through a straightforward Schiff base reaction and analyzed using various spectroscopic techniques. The chemosensing potential of JulAmino-Tris was investigated using UV-vis and fluorescence spectroscopy in a partially aqueous medium. The pristine form of JulAmino-Tris in pure dimethyl sulphoxide (DMSO) is non-fluorescent due to PET, ESIPT, and ICT processes. JulAmino-Tris probe showed turn-on fluorescence behavior in the presence of Al³⁺, while other metal ions remained non-responsive. The probe emits cyan fluorescence upon binding to Al³ ⁺, inhibiting these processes. The 1:1 non-covalent complex formation and detection mechanism was confirmed through Job's plot, mass spectrometry, ¹H NMR titration, and DFT calculations, with a detection limit of 25 nM. The JulAmino-Tris probe demonstrated low cytotoxicity and efficacy in Zebrafish imaging studies and its utility in detecting Al³ ⁺ in water and drug samples.