Micro-nano FeS-flower-decorated rGO nanosheets for enhanced catechol biosensing

Phenolic compounds, including catechol, pose significant environmental threats due to their high toxicity and low biodegradability. However, owing to the complex procedures, high cost, and low specificity of the present detection techniques, the on-site and real-time monitoring of catechol in real water remain challenging for practical use. In this work, we developed a FeS-rGO micro-nanocomposite-based biosensor for trace catechol detection in water. The material was engineered through a hydrothermal and oriented self-assembly approach that enabled in-situ growth of flower-like FeS on rGO, effectively preventing FeS agglomeration and enhancing interfacial integration. This designed structure synergistically combines the high surface area of FeS with the conductivity of rGO, promoting efficient electron transfer and catalytic activity. After laccase immobilization, the biosensor exhibits high selectivity for catechol against interfering phenols, with a sensitivity of 253 μA·mM −1 ·cm −2 and a broad linear range from 10 nM to 8.12 mM, which demonstrates potential application in the early-warning and treatment of environmental pollutant leakage.