Electrochemiluminescence Resonance Energy Transfer Biosensor for the Human-Associated Clade of Streptococcus suis Based on Prereduction-Enhanced Yttrium MOFs

Streptococcus suis, a significant zoonotic pathogen, annually caused substantial economic losses in the swine industry and had intensified threat to public health due to the recent emergence of human-associated clade. In this study, we discovered that the rare-earth metal-based metal–organic frameworks (Y-BTC) possessed excellent ECL capabilities. After prereduction at high voltage, its ECL intensity was enhanced by two times. Subsequently, we developed an efficient CRISPR/Cas12a-mediated electrochemiluminescence resonance energy transfer (ECL-RET) biosensor utilizing Y-BTC for the detection of the human-associated S. suis clade. Y-BTC was employed as the ECL-RET donor and ECL emitter, and the spherical nucleic acid Au NP was utilized as the ECL-RET receptor. In the presence of the target, isothermal amplification was triggered to generate a large number of amplicons, which subsequently activated the trans -cleavage activity of Cas12a. Cas12a cleaved the nucleic acid shell on the surface of Au NPs, reducing the spatial distance between Au NPs and Y-BTC due to electrostatic adsorption, thereby quenching the ECL of Y-BTC via ECL-RET. Consequently, the presence of targets can be observed by a reduced ECL signal. The sensor exhibited a detection range of 25 pM to 50 nM, with a detection limit as low as 17 pM. The practical utility was verified through actual sample testing. Our proposed ECL-RET sensing strategy provides a new avenue for the sensitive detection of S. suis . The universality has also been demonstrated using Fusobacterium nucleatum, Salmonella pullorum, and Listeria monocytogenes, holding great promise in the field of food safety and public health.