Signal “off-on” electrochemical aptamer sensing of interleukin-6 based on platinum nanoparticles/MIL-88B MOF nanozyme

• A signal “off-on” electrochemical aptamer sensing platform was designed for IL-6. • The prepared Pt/MIL nanozyme exhibits superior catalytical activity which can be controlled by the IL-6 aptamer. • This approach combines simplicity, reliability, and adaptability, offering a novel strategy for biomedical diagnostics. Interleukin-6 (IL-6), a prevalent proinflammatory cytokine, serves as a critical biomarker for diseases such as nasopharyngeal carcinoma, pancreatitis, infections, and cardiovascular disorders, necessitating the development of robust monitoring strategy. To address this, herein we introduce an innovative “off-on” electrochemical aptamer (Apt) sensing platform for IL-6 detection based on platinum nanoparticle-loaded MIL-88B MOF (Pt/MIL) nanohybrid as nanozyme. This platform operates via the Pt/MIL catalytic conversion of 1,2-diaminobenzene into electroactive diaminophenazinc (DAP). In the absence of IL-6, Apt binding to the Pt/MIL nanozyme surface obstructs its enzymatic activity, suppressing DAP generation and resulting in a low current signal (“off” state). Upon IL-6 introduction, the specific Apt-IL-6 interactions displace the Apt from the nanozyme surface, restoring catalytic activity and amplifying DAP production (“on” state). Optimization of experimental parameters yielded a highly sensitive and selective detection system for IL-6, thus demonstrating potential as a versatile platform for interleukin detection through Apt modification. This approach combines simplicity, reliability, and adaptability, offering a novel strategy for biomedical diagnostics.