Liang_2026_Talanta_310_130140

The detection of trace organophosphorus (OPs) pesticides is crucial yet remains challenging for environmental monitoring and food safety. Although enzyme-based electrochemical sensors provide good selectivity, their sensitivity is often limited by inefficient electron transfer and poor mass transport. Herein, we report a novel strategy that synergistically integrates a three-dimensionally ordered macroporous (3DOM) In(2)O(3) framework with atomically dispersed Ru single atoms to construct an acetylcholinesterase-based biosensor for ultrasensitive detection of malathion. In contrast to conventional nanoparticle-modified electrodes, this design combines the structural advantage of a 3DOM architecture, which enhances mass transport, with the electronic effect of Ru single atoms that accelerate electron transfer and promote the electrocatalytic oxidation of thiocholine, resulting in significant signal amplification. As a result, the biosensor exhibits an exceptionally wide linear range from 3.075 pg mL(-1) to 30.75 ng mL(-1) and an ultralow detection limit of 0.459 pg mL(-1), outperforming most reported OP sensors. In addition, it demonstrates excellent stability, reproducibility, and satisfactory recoveries ranging from 97.5% to 107.3% in real sample analysis. This work provides a new paradigm for constructing advanced electrochemical biosensors based on single-atom-engineered macroporous scaffolds and offers a promising approach for high-performance environmental monitoring.