Novel Nanozymes with Sample Pretreatment Function for Specific Multimodal Detection of Perfluorooctanesulfonate

Perfluorooctanesulfonate (PFOS), a ubiquitous and persistent organic pollutant, poses severe health risks due to its bioaccumulation and recalcitrance. Despite existing detection methods, the need for rapid, sensitive, and cost-effective PFOS quantification remains unmet, particularly for on-site and mass sample analysis. Here, we introduce an innovative "three-in-one" multifunctional nanohybrid, <b>Fe</b>_<b>3</b><b>O</b>_<b>4</b><b>@MON-F@Ru</b>, which revolutionizes the detection of PFOS through a novel integration of nanozymes and microporous organic networks (MONs). This nanohybrid enables sensitive colorimetric and photothermal signaling for PFOS detection, addressing the long-standing challenge of selectivity in nanozyme-based analytical methods. The Fe₃O₄ core enables magnetic separation, while the fluorinated MONs shell specifically interacts with PFOS through F-F bonding and electrostatic forces, concurrently serving as a high-density carrier for Ru nanozymes. The presence of PFOS significantly inhibits catalytic activity, offering a rapid and specific colorimetric method with a detection limit as low as 15.4 nM. Additionally, based on the near-infrared (NIR) laser-driven photothermal properties of oxidized 3,3',5,5'-tetramethylbenzidine (TMB), the photothermal analysis for PFOS detection was also established. This study not only advances the design of nanozymes with integrated sample pretreatment capabilities but also pioneers a portable, dual-signaling sensing strategy for PFOS detection, offering profound implications for environmental monitoring and public health safety.