Salicylaldehyde built fluorescent probe for dual sensing of Al 3+ , Zn 2+ ions: Applications in latent fingerprint, bio-imaging & real sample analysis.

This Schiff base chemosensor (SNN) detected dual ions, Al ³⁺ and Zn ²⁺ ions selectively. Fluorescence spectrum investigations showed that Al ³⁺ ions increased fluorescence intensity, notably at 493 nm. Introducing Zn ²⁺ 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 ³⁺ /Zn ²⁺ 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 ³⁺ and SNN + Zn ²⁺ complexations had a 1:1 stoichiometry. DFT, LC-HRMS, and ¹ H NMR titration confirm this conclusion. The probe SNN's limit of detection (LOD) for Al ³⁺ /Zn ²⁺ 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 ³⁺ and Zn ²⁺ ions.
Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
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