CRISPR-enhanced low-potential ECL sensor based on AuPt-functionalized porphyrin AlOG for ultrasensitive aflatoxin B1 detection.

Abstract

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.