This study was aimed at establishing a novel visual detection method for SARS-CoV-2 based on magnetic beads(MBs)enrichment and Au@Pt nanoparticles(Au@PtNPs)enzyme catalysis.According to the double-antibody sandwich method,MBs conjugated with SARS-CoV-2 antibody 1 enriched SARS-CoV-2 antigen in samples.After magnetic adsorption,separation,and washing,the enriched antigen reacted with Au@PtNPs labeled with SARS-CoV-2 antibody 2,thereby forming an immune com-plex.After another round of magnetic adsorption and washing,the color change was catalyzed by Au@PtNPs in the chromogenic solu-tion,and the results were determined through comparison of color changes:a blue color change indicated a positive result,whereas no obvious color change indicated a negative result.The sensitivity and specificity of this method were evaluated.This study successfully established a visual detection method based on MBs enrichment and Au@PtNPs enzyme catalysis for targeting SARS-CoV-2 antigens.The method was able to detect SARS-CoV-2 antigens within 30 minutes and SARS-CoV-2nucleocapsid protein samples with antigen concentrations above 3.125 ng/mL.The method showed no cross-reactivity with seasonal influenza(H1N1)or influenza B virus nu-cleoprotein.The visual detection method established in this study,based on Au@PtNPs enzyme catalysis and MBs enrichment,has high specificity and sensitivity,is simple and quick to operate,and provides a new approach for rapid viral detection.

This study was aimed at establishing a novel visual detection method for SARS-CoV-2 based on magnetic beads(MBs)enrichment and Au@Pt nanoparticles(Au@PtNPs)enzyme catalysis.According to the double-antibody sandwich method,MBs conjugated with SARS-CoV-2 antibody 1 enriched SARS-CoV-2 antigen in samples.After magnetic adsorption,separation,and washing,the enriched antigen reacted with Au@PtNPs labeled with SARS-CoV-2 antibody 2,thereby forming an immune com-plex.After another round of magnetic adsorption and washing,the color change was catalyzed by Au@PtNPs in the chromogenic solu-tion,and the results were determined through comparison of color changes:a blue color change indicated a positive result,whereas no obvious color change indicated a negative result.The sensitivity and specificity of this method were evaluated.This study successfully established a visual detection method based on MBs enrichment and Au@PtNPs enzyme catalysis for targeting SARS-CoV-2 antigens.The method was able to detect SARS-CoV-2 antigens within 30 minutes and SARS-CoV-2nucleocapsid protein samples with antigen concentrations above 3.125 ng/mL.The method showed no cross-reactivity with seasonal influenza(H1N1)or influenza B virus nu-cleoprotein.The visual detection method established in this study,based on Au@PtNPs enzyme catalysis and MBs enrichment,has high specificity and sensitivity,is simple and quick to operate,and provides a new approach for rapid viral detection.