Detection of salbutamol and enantioselective sensing of l/d-lysine based on a cadmium-based coordination polymer

Abstract

In this work, a one-dimensional zigzag chain coordination polymer, {[Cd(pbca)₂]·2C₂H₅OH}_n (1), was synthesised using the 2-(pyridin-2-yl)-1H-benzoimidazole-5-carboxylic acid (Hpbca) ligand and transition metal salts in a water/ethanol solvent system. Compound 1 further forms a three-dimensional supramolecular structure through hydrogen-bonding interactions. The fluorescence probe properties showed that the activated solvent-free sample of compound 1 (denoted as 1a) can be used to quantitatively identify salbutamol, and also it could distinguish L/D-lysine by different fluorescence responses, the detection limits of salbutamol and L-lysine were 1.22 × 10⁻⁷ M and 1.44 × 10⁻⁷ M, respectively. It was found that compound 1a had excellent anti-interference properties and recyclability for the detection of the above substances. Meanwhile, the fluorescence response mechanisms of compound 1a for different analytes were elucidated through characterization using FT-IR, PXRD, and DFT calculations and the Benesi–Hildebrand equation. This study not only provides a viable sensor for the sensitive and selective detection of salbutamol in simulated urine samples but also provides a promising strategy for achieving the fluorescence identification of chiral amino acids by using achiral coordination polymers.