Suction-Cup-Inspired Fluorescence Turn-on for Integrated Capture and Synergistic Photocatalytic Inactivation of Cronobacter sakazakii

Cronobacter sakazakii (C. sakazakii) poses a severe threat through contaminated powdered dairy products, necessitating rapid, specific, and effective strategies for its complete management. This work presents a capture-inactivate-detect platform based on an antibody-functionalized magnetic ZIF (Ab-M@ZIF) and a polydopamine-coated AIE photosensitizer (PDA@TPE). The platform enables immunomagnetic capture and generates ROS, while releasing Co2+ ions to permeabilize membranes, weakening their barrier function. Mechanistic studies indicate that the catechol-functionalized flexible PDA shell mediates strong binding to bacterial surfaces, leading to the subsequent generation of a potent ROS storm under light irradiation. Remarkably, this synergistic action achieves a 6-log reduction in bacterial viability within 45 min under visible light. This binding-triggered AIE response enables sensitive detection of C. sakazakii with an LOD of 4.13 CFU/mL. The platform demonstrated recovery rates of 84.01-97.07% (RSD 3.42-8.71%) and complete sterilization in real milk. Biosafety assessments confirm negligible in vitro and in vivo toxicity, with cell viability over 85% at 1 mg/mL under irradiation, verifying fine biocompatibility. This study provides a novel synergistic strategy that combines precise capture, synergistic inactivation, and sensitive detection into a single system, offering a promising solution for enhancing dairy product safety.