One stone two birds: electrochemical and colorimetric dual-mode biosensor based on copper peroxide/covalent organic framework nanocomposite for ultrasensentive norovirus detection

Norovirus (NoV) is regarded as one of the most common causes of foodborne diarrhea in the world. It is urgent to identify the pathogenic microorganism of the diarrhea in short time. In this work, we developed an electrochemical and colorimetric dual-mode detection for NoV based on the excellent dual catalytic properties of copper peroxide/COF-NH₂ nanocomposite (CuO₂@COF-NH₂). For the colorimetric detection, NoV can be directly detected by the naked eye based on CuO₂@COF-NH₂ as a laccase-like nonazyme using "peptide-NoV-antibody" recognition mode. The colorimetric assay displayed a wide and quality linear detection range from 1 to 5000 copies/mL of NoV with a low limit of detection (LOD) of 0.125 copy/mL. For the electrochemical detection of NoV, CuO₂@COF-NH₂ showed an oxidation peak of copper ion from Cu⁺ to Cu²⁺ using "peptide-NoV-antibody" recognition mode. The electrochemical assay showed a linear detection range was 1-5000 copies/mL with a LOD of 0.152 copy/mL. It's worthy to note that this assay does not need other electrical signal molecule, which provide the stable and sensitive electrochemial detection for NoV. The electrochemical and colorimetric dual-mode detection was used to detect NoV in foods and faceal samples, which has the potential for improving food safety and diagnosing of NoV-infected diarrhea.