CRISPR-enhanced low-potential ECL sensor based on AuPt-functionalized porphyrin AlOG for ultrasensitive aflatoxin B1
Li Song1, Shuchun Bu1, Yilan Ding1
1Key Laboratory of Luminescence Analysis and Molecular Sensing (Southwest University), Ministry of Education, Chongqing Engineering Laboratory of Nanomaterials & Sensor Technologies, College of Chemistry and Chemical Engineering, Southwest University, Chongqing, 400715, PR China.
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Herein, an ultrasensitive low-potential electrochemiluminescence (ECL) sensor was developed by integrating an AuPt nanoparticle-functionalized porphyrin aluminum-organic gel (P-AlOG@AuPt) emitter with an enhanced CRISPR/Cas12a amplification module for the detection of aflatoxin B1 (AFB1) related to food safety. Impressively, the P-AlOG@AuPt emitter exhibited strong ECL emission and high signal-to-noise ratio at a low triggering potential (-0.8 V), addressing key limitations of previous high-potential aluminum-organic gels. Meanwhile, the in situ enriched AuPt as a coreaction accelerator catalyzed the reduction of coreactant S2O82- to produce abundant SO4•- for facilitating its interactions with P-AlOG@AuPt•-, resulting in a significant ECL enhancement. Furthermore, a synergistic catalytic hairpin assembly (CHA) pre-amplification and tetrahedral DNA nanostructure (TDN)-anchored ssDNA reporters significantly improved the cleavage efficiency of CRISPR/Cas12a, boosting the detection sensitivity of the ECL sensor for AFB1. The established ECL sensor exhibited ultrasensitive detection of AFB1 with a linear range of 0.1 pg mL-1 - 500 ng mL-1 and detection limit of 0.044 pg mL-1, outperforming most reported ECL- and CRISPR-based AFB1 sensors. The practical usability of the proposed ECL sensor was verified by applying it for the quantification of AFB1 in rice samples. This work offers a promising low-potential ECL sensing platform for practical mycotoxin monitoring and broader biosensing applications.
