Rational Design of Bismuth-Based Metal–Organic Framework Electrochemiluminescence Sensing Platform: A Proactive Approach for Early Warning of Mycotoxin Contaminants

Exploring a proactive control strategy for early assessment of toxigenic potential is of great significance in preventing health risks and economic losses. This study proposes an efficient electrochemiluminescence (ECL) protocol for ultrasensitive detection of the ochratoxin A (OTA) biosynthesis key gene, the halogenase gene (halA), enabling intervention before mass toxin production. An ECL system was developed using a bismuth-based metal–organic framework (Bi-TBAPy MOF) as an emitter. This material integrates low-toxicity, highly biocompatible Bi3+ ions with a 1,3,6,8-tetrakis(4-carboxyphenyl)pyrene (H4TBAPy) organic ligand exhibiting aggregation-induced emission enhancement characteristics. The rigid coordination network of the MOF effectively suppresses the ligand’s aggregation-caused quenching effect, significantly enhancing ECL efficiency (2.4-fold higher luminescence intensity than H4TBAPy aggregates). The proposed biosensor achieved ultrasensitive detection of the halA gene fragment (detection limit: 0.84 fM; linear range: 1 fM to 100 nM), providing early warning of toxigenic fungal activity. This work not only provides a practical approach for developing high-performance ECL emitters but also establishes a key technical foundation for constructing proactive mycotoxin control systems in agricultural supply chains, demonstrating significant implications for safeguarding food safety and reducing economic losses.