Salicylaldehyde built fluorescent probe for dual sensing of Al, Zn ions: Applications in latent fingerprint, bio-imaging & real sample analysis.

This Schiff base chemosensor (SNN) detected dual ions, Al and Zn ions selectively. Fluorescence spectrum investigations showed that Al ions increased fluorescence intensity, notably at 493 nm. Introducing Zn ions caused a significant blue shift of roughly ∼65 nm at a wavelength of 434 nm, resulting in a notable change in fluorescence intensity. When binding Al/Zn ions, the SNN receptor uses three methods. Inhibition of photoinduced electron transfer (PET), excited state intramolecular proton transfer (ESIPT), and restriction of CN isomerization. The jobs plot method found that SNN + Al and SNN + Zn complexations had a 1:1 stoichiometry. DFT, LC-HRMS, and H NMR titration confirm this conclusion. The probe SNN's limit of detection (LOD) for Al/Zn ions was 3.99 nM and 1.33 nM. Latent fingerprint (LFP), food samples, pharmaceutical products, and E. coli pathogen bio-imaging have all used the SNN probe to identify Al and Zn ions.