A Zinc-Based Coordination Supramolecule Sensor for Sensitive Detection of Salbutamol Molecule

As a banned substance misused in doping drugs and lean meat powders, salbutamol (SAL) poses a potential threat to human health. Here, a luminescence zinc-based coordination supramolecule sensor was constructed from 2-(2′-pyridyl)benzimidazole-5-carboxylic acid (Hpbca) ligand and zinc sulfate in the self-assembly process under solvothermal conditions, namely, [Zn₂(pbca)₂(SO₄)(H₂O)₃] (1), which could function as an efficient fluorescence probe for the detection of SAL. The single-crystal X-ray diffraction analysis reveals that complex 1 possesses distinctive binuclear building units, which are interlinked to form a three-dimensional supramolecule framework through the interactions of π···π stacking and hydrogen bonding. Complex 1 demonstrated exceptional performances with a high sensitivity (the limit of detection: 0.357 ppm), excellent anti-interference, and rapid response time. The fluorescence sensing mechanism of complex 1 toward SAL was systematically investigated through comprehensive experiments and DFT calculations. For practical implementations, we developed portable low-cost test strips by incorporating complex 1 into polymer materials, which enabled visual SAL detection through distinct color changes under the UV irradiation of 365 nm. These composite films exhibited reliable performance in recognizing SAL with the naked eye, offering promising feasibility for on-site monitoring in the fields of anti-doping and food safety.