An Al(iii) and Hg(ii) selective optical and fluorometric chemosensor and its application in prawn, pharmaceutical drug, and in vitro cell imaging

Abstract

This study presents the design, synthesis, and characterization of a novel chemosensor, L, derived from the condensation reaction between rhodamine B and N,N-dimethyl-1,3-diaminopropane. Spectroscopic methods, including Fourier transform infrared (FTIR), ultraviolet-visible (UV-vis), mass and nuclear magnetic resonance (NMR) spectrometry, confirm the structure of L. L selectively detects Al(III) and Hg(II) ions in a 9 : 1 DMSO–water solution, exhibiting enhanced fluorescence and a noticeable color shift. The sensing mechanism involves a structural change, including spirolactam ring opening, which significantly increases the emission intensity. Binding tests revealed a 1 : 1 stoichiometric ratio between L and the target metal ions. The chemosensor's potential has been demonstrated through the detection of Hg(II) in prawns and Al(III) in pharmaceutical samples. Additionally, cell imaging studies validate L's biosensing ability. DFT calculations optimized the ideal structure of the probe–analyte complex.