Enhanced Electrochemical Sensing of Butylated Hydroxy Anisole through Hollow Metal–Organic Frameworks with Gold Nanoparticles and Enzymes

Reliable methods for detecting butylated hydroxy anisole (BHA) in food and pharmaceutical products are crucial due to its potential toxicity. The utilization of hollow zeolite imidazolate framework-8 (ZIF-8) as host materials possessing both conducting and enzymatic properties presents a promising electrochemical sensing material. Herein, a facile synthesis strategy of ternary nanocomposite HRP@HZIF-Au was proposed, which involves the immobilization of horse radish peroxidase (HRP) into ZIF-8 through a coprecipitation method. Then, a hybrid porous HRP@HZIF was etched with tannic acid, which is further functionalized with gold nanoparticles (Au NPs). The HRP@HZIF-Au nanomaterial tends to be spherical with a size of about 550 nm. The resulting HRP@HZIF-Au electrochemical sensor exhibits a significant electrocatalytic performance for detecting BHA, which has an extended linear detection range of 0.1 to 1600 μmol L–1 and a low detection limit of 0.03 μmol L–1 (S/N = 3). Remarkably, the HRP@HZIF-Au electrochemical sensor demonstrates good interference selectivity and storage stability (∼20 days). The remarkable catalytic efficiency of HRP@HZIF-Au for BHA may be attributed to synergistic effects arising from hollow ZIF-8, HRP-promoted electron transfer, and Au NPs.