Engineering the microenvironment of UiO-66 via ligand functionalization for efficient patulin detoxification in apple...

Patulin (PAT) is a mycotoxin commonly found in apple products, which poses significant health risks and is challenging to remove using conventional methods. This study employed a ligand functionalization strategy to precisely modulate the microenvironment of metal-organic frameworks and investigate its impact on PAT adsorption performance.

A series of functionalized UiO-66 nanomaterials (UiO-66, UiO-66-NH₂, and UiO-66-SH) were synthesized via solvothermal method using zirconium as the metal node and terephthalic acid derivatives as organic linkers. Comprehensive characterization confirmed the successful incorporation of the corresponding functional groups and the conserved crystalline structure of the UiO-66. Screening of their adsorption capabilities revealed a dramatic dependence on the surface chemistry, with UiO-66-SH exhibiting superior PAT adsorption performance and achieving complete removal under optimized conditions. Adsorption kinetics and isotherm studies were conducted. The results demonstrated that the adsorption process of UiO-66-SH toward PAT followed a pseudo-second-order kinetics model and the Langmuir adsorption isotherm, indicative of chemisorption-driven monolayer adsorption. The maximum adsorption capacity was determined to be 18.209 μg mg^-1. Mechanistic investigations confirmed that the thiol groups on UiO-66-SH chemically interacted with PAT via a Michael addition reaction, thereby achieving efficient adsorption and removal of PAT. In practical application, UiO-66-SH effectively removed PAT from spiked apple juice while maintaining the key quality parameters of apple juice.

Our study demonstrates that ligand-induced microenvironment modulation renders UiO-66-SH a highly efficient and selective adsorbent for PAT decontamination, offering a promising strategy for enhancing the safety of apple products. © 2026 Society of Chemical Industry.