Shape-Specific\nGold Nanoparticles for Multiplex Biosensing\nApplications

The biosensing field faces a significant challenge in\nefficiently\ndetecting multiple analytes in a single diagnostic sample in order\nto compete with other established multiplex molecular diagnostic technologies\nsuch as PCR and ELISA. In response, we have developed a colorimetric\nnanobiosensor based on multiple morphological forms of functionalized\ngold nanoparticles (AuNPs) for the simultaneous detection of the influenza\nvirus and SARS-CoV-2 virus. Gold nanospheres (GNSp) were modified\nwith oligonucleotides specific for the influenza A virus, while gold\nnanoshells (GNSh) were modified with oligonucleotides specific for\nthe SARS-CoV-2 virus. In the presence of their respective targets,\nAuNPs remain stable due to DNA–DNA interactions; conversely,\nin the absence of targets, AuNPs aggregate. Consequently, the hybrid\nsystem exhibits an indigo color with the SARS-CoV-2 target, a blue\ncolor with the Influenza A target, and a purple color with both targets,\nvisible to the naked eye. Analytical sensitivity was 100 nM, and no\ncross-reactivity was observed with potentially confounding pathogens.\nThis approach holds great promise for the simultaneous identification\nof multiple pathogens in a rapid manner without the need for equipment\nor trained personnel.