Highly sensitive multiplex lateral flow immunoassay of phytopathogens using Au@Pt nanoparticles as the colorimetric and catalytic label

A device for multiplex lateral flow immunoassay (LFIA) of major viral (potato viruses X and Y, potato leafroll virus) and bacterial (Ralstonia solanacearum, Clavibacter michiganensis, Dickeya solani, Pectobacterium atrosepticum) potato pathogens was developed. The device includes test strips connected with the central fiberglass reservoir. The addition of the probe (300 µL) to the reservoir initiates the migration of the liquid along membranes and the formation of immune complexes labeled with Au@Pt nanosized label. Besides the own Au@Pt coloration, the colorimetric signals are enhanced using the peroxidase-mimicking activity of Au@Pt. The developed device facilitated rapid (15 min), multiplex (7 targets), and highly sensitive LFIA for viral (330-480 pg/mL) and bacterial (500-104 cells/mL) pathogens. © 2021 Author(s).