Integrated Aptamer-Functionalized Fe/Mn-MOF Nanozyme Membrane Coupling Selective Pathogen Capture with Colorimetric Transduction

Abstract Developing nanozyme-based biosensors that integrate high catalytic activity, selective target capture, and target-responsive signaling remains challenging for rapid on-site pathogen detection. In this work, we develop an integrated aptamer-functionalized Mn-doped Fe metal−organic framework (Apt-Fe/Mn-MOF) membrane that combines selective target capture, matrix removal, and colorimetric transduction within a single sensing platform for the rapid detection of Vibrio parahaemolyticus. The catalytic interface was engineered via Mn incorporation to weaken the overly strong binding of oxygenated intermediates at Fe sites, thereby improving the intrinsic peroxidase-like activity of Fe/Mn-MOF. Upon selective target capture by the Apt-Fe/Mn-MOF membrane and subsequent washing to remove unbound matrix components, the membrane-retained V. parahaemolyticus directly modulated the Fe/Mn-MOF catalytic interface, resulting in concentration-dependent catalytic suppression and a measurable colorimetric response. The platform achieved a linear detection range of 10−107 CFU/mL and a detection limit of 3 CFU/mL within a total assay time of 30 min. These results demonstrate the applicability of the Apt-Fe/Mn-MOF membrane as an integrated sensing platform that combines target capture, matrix removal, and direct signal transduction for V. parahaemolyticus detection in complex samples.