Preparation of AuPt@ZIF-67 nanomaterials and their application in a flow injection chemiluminescence immunoassay†

Compared to natural enzymes, which are prone to deactivation, require expensive purification processes, and have stringent storage demands, nanozymes demonstrate superior stability, cost-efficiency, and customizable catalytic performance. In this study, AuPt@ZIF-67 nano-enzyme composites with high catalytic activity were constructed by loading Au and Pt nanoparticles onto zeolitic imidazolate framework-67 (ZIF-67). Capitalizing on the porous structure of ZIF-67 and the electronic synergy between the Au–Pt bimetallic components, the material demonstrated exceptional peroxidase-like activity. Harnessing the engineered properties of this advanced nanomaterial, a flow-injection chemiluminescence immunoassay (FI-CLIA) platform was prepared to achieve ultrarapid and ultrasensitive monitoring of aflatoxin B1 (AFB1) in foodstuffs. Experimental results indicated a linear dynamic range of 0.002–1000 ng mL⁻¹ for AFB1 quantification, achieving an ultralow detection limit of 0.68 pg mL⁻¹ (S/N = 3). The spiked recovery rates for corn and wheat samples ranged from 81.5% to 110.3%. The findings indicate that this method exhibits significant applicability prospects for AFB1 detection in actual sample analysis.