Phage adsorption-driven colorimetric broad-spectrum detection of foodborne Enterobacter hormaechei using phage-modified NH2-MIL-88B(Fe) nanozyme

Enterobacter hormaechei, A zoonotic pathogen with escalating prevalence in global food sources, severely jeopardizes food safety, necessitating the development of high-performance detection methods. Herein, a novel colorimetric detection strategy integrating phages and nanozymes was proposed for foodborne E. hormaechei. Initially, four homologous phages (EhpYZU05, EhpYZU08, EhpYZU9–1 and EhpYZU10), which were isolated using E. hormaechei YZU05 as the host bacterium, were modified on the surface of NH₂-MIL-88B(Fe) to fabricate four phage@NH₂-MIL-88B(Fe) nanozymes. These nanozymes exhibit peroxidase-like activity, catalyzing 3,3′,5,5′-tetramethylbenzidine (TMB) chromogenic reaction in presence of H₂O₂. With introduction of multiple host or non-host E. hormaechei strains, TMB chromogenic reaction catalyzed by phage@NH₂-MIL-88B(Fe) nanozymes can be specifically inhibited. This inhibition occurs due to the specific phage adsorption of phage@NH₂-MIL-88B(Fe) nanozymes towards these host or non-host E. hormaechei strains, indirectly blocking their catalytic sites. Leveraging this principle, colorimetric broad-spectrum detection of E. hormaechei was achieved. Additionally, this method demonstrated reliable recoveries (96.7 % ~ 103.3 %) when applied to detect real food matrices, highlighting its high reliability in practical scenarios. This approach not only clarifies the intrinsic mechanism of phage-modified nanozymes for target bacteria detection but also provides a robust and reliable method for early pathogen detection, thereby significantly contributing to food safety enhancement