An Adaptive Trimodal Bioanalysis System via Heterogeneous Interface Engineering and Enzyme-Powered Molecular Machines

This study reports a trimodal biosensing platform centered on an adaptive signal-fusion strategy for the ultrasensitive detection of pathogens, developed through the strategic integration of heterogeneous interface engineering and enzyme-powered molecular machines. The platform is built on a Ni-MOF-on-Co-MOF heterostructure, where precise interface modulation and pore channel engineering significantly enhance the specific surface area and electron-transport efficiency (1.55-fold higher enzyme-loading capacity), complemented by a novel Au@Ni/Co ZIF@PDA with a remarkable 38.1% photothermal conversion efficiency. For the detection mechanism, the system synergistically combines exonuclease III-mediated target cycling with a dual-output toehold-mediated strand displacement-DNA Walker cascade amplification strategy, which achieves exponential signal amplification by releasing double the signal probes per reaction cycle. This integrated design enables electrochemical, colorimetric, and photothermal trimodal output, with exceptional detection limits (LOD, S/N = 3) of 31.4 aM, 1.32 fM, and 1.14 fM respectively, alongside built-in self-verification and correction for enhanced reliability. Practical validation with real samples shows strong agreement with qPCR results, high spiked recovery rates (96.1-103.4%), excellent repeatability, and outstanding stability. Consequently, this trimodal system presents a novel, robust approach for pathogen detection and, via its adaptive intelligent multisignal cross-checking, offers a highly promising technological platform for complex sample analysis in early agricultural disease diagnosis, food safety monitoring, and clinical diagnostics.