Myeloperoxidase-responsive materials for infection detection based on immobilized aminomethoxyphenol

There is a strong need for simple and fast diagnostic tools for the detection of wound infection. Immune system-derived enzymes like myeloperoxidase are efficient biomarkers for wound infection that emerge in the early stage infection process. In this study, 5-amino-2-methoxyphenol was functionalized with alkoxysilane to allow visual detection of MPO on carrier materials, for example, in test strips. Indeed, MPO activity was visually detectable in short time in wound background. Oxidation of the substrate was followed spectrophotometrically and proved via HPLC. LC-ESI TOF and NMR analyses unveiled the reaction mechanism and a dimeric reaction product responsible for the visualization of MPO activity. The substrate specificity and sensitivity toward MPO detection was proved and tests with infected wound fluids were successfully performed. The study demonstrates the suitability of the novel MPO substrate for the detection of wound infection and the covalent immobilization on diagnostic carrier materials.