Built-in capacitive biosensor based leveraging rolling circle amplification-architected bimetallic nanozyme/glucose oxidase catalytic forest for overcoming sensitivity limits in plant pathogen monitoring

Abstract

Sugarcane smut, responsible for 35–60 % yield losses and 18–22 % sugar content reductions, demands early diagnostic solutions to mitigate its agricultural impact. Current methods like qPCR remain constrained by limited sensitivity and reliance on centralized laboratory infrastructure. To address these challenges, a field-deployable biosensing platform is developed via the integration of three synergistic innovations: a rolling circle amplification-engineered catalytic “nanozyme forest” that achieves high-density immobilization of Au-Pt bimetallic nanozymes and glucose oxidase active sites; an entropy-driven DNA strand displacement amplification system employing multi-recognition probes for sequence-specific capture and signal amplification of the pathogen biomarker bE4’; and a dual-functional Au@CoV-MOF electrode that simultaneously enables pseudocapacitive energy storage and enhances interfacial electron transfer. The biosensor demonstrates a linear detection range from 10⁻¹⁶ to 10⁻⁸ M with a 24.86 aM detection limit, surpassing qPCR sensitivity by two orders of magnitude while maintaining single-base mismatch discrimination. Field validation using sugarcane samples shows complete diagnostic concordance with qPCR results but reduces assay time through elimination of nucleic acid extraction and thermal cycling requirements. By synergizing enzymatic cascade amplification with self-powered energy storage, this work establishes a new paradigm for plant pathogen diagnostics that bridges the gap between laboratory-grade sensitivity and field-deployable practicality.