A pyridine naphthalene conjugate: ESIPT based molecular chemosensor for Al3+ ions and sequential detection of H2PO4- and applications in milk, water samples and bio-imaging.

A fluorescent probe (HL) with an "off-on-off" feature was created to identify Al3+ ions in aqueous solutions. The probe can identify Al3+ ions while other metal ions are present, and it is made to be straightforward to use. The probe was built utilizing a Schiff-base chemosensor, 1-[(pyridin-2-ylimino)] naphthalene-2-ol (HL), and a variety of spectroscopic methods were employed to describe it. Probe HL' s sensing ability was assessed in a 1:1 volumetric ratio THF/H 2 O medium, and to establish the binding with Al3+ ions, several spectroscopic methods such as 1H NMR titration analysis, ESI-MS technique including DFT analysis were used. The probe HL showed notable alterations in fluorescence emission spectra during the detection of Al3+ and H 2 PO 4 - in the presence of other competing ions. The value of the association constant and the detection limit for Al3+ and H 2 PO 4 - were found to be 8.51×104 M-1 and 5.5×102 M-1, respectively. Besides, its applications as tests using milk and water samples successfully identified Al3+ ions in the presence of the probe HL. Additionally, probe HL was successfully examined in E.Coli pathogen for the sensing of Al3+ and H 2 PO 4 - ions [Display omitted] • An "off-on-off" probe (HL) was utilized for the detection of Al3+ and H 2 PO 4 - ions. • Inhibition of PET, C N isomerization & ESIPT process involved in binding mechanism. • LOD was calculated to be 3.15 μM for Al3+ detection by fluorimetry sensing of HL. • 1:1 binding stoichiometry was confirmed by 1H NMR titration, ESI-MS & DFT analysis. • Food, water sample analysis & Bio-imaging for HL in the detection of Al3+ ions. [ABSTRACT FROM AUTHOR]