Iridescent polymeric film with tunable color responses to ultra-trace Staphylococcus aureus enterotoxin B

Colorimetric sensing materials have a rising demand in detection applications, especially in the field of naked-eye detection. Herein, a novel iridescent polymeric film that can respond to different Staphylococcus aureus enterotoxin B (SEB) concentrations in the visible range is reported. This film is fabricated by polymerization of methacrylic acid (MAA) and ethylene dimethacrylate (EGDMA) owing an inverse opal array (IOA) structure, and gold nanoparticles (AuNPs) are enchased on the polymer skeleton. This composite structure facilitates the film to respond to SEB at a LOD of 4.29 fg mL −1 , making it the best performing colorimetric material to date. Cryo-Scanning Electron Microscopy and 3D AFM were used to observe the morphology change of the iridescent polymeric film after SEB binding. This film possesses great advantages for ultrasensitive visual detection of real samples. In addition, the iridescent polymeric film has the potential to become a universal sensing material, realizing the ultrasensitive visual detection of hazardous substances without equipment in the field by replacing the recognition element.