DEVELOPMENT OF LATERAL FLOW IMMUNOASSAY WITH DOUBLE ENHANCEMENT FOR PLANT VIRUS DETECTION: A CASE STUDY WITH POTATO VIRUS X

Crop loss due to pathogens is one of the main reason of food shortage. Potato virus X is one of the main phytopathogens of potatoes, losses from it can reach up to 40%. Thus, a rapid and sensitive method for its early detection is necessary and modern methods of disease diagnosis can significantly reduce potato yield losses. The aim of this study is to develop lateral flow immunoassay (LFIA) with amplification for the detection of PVX in low concentrations. Two types of amplification were used: 1) magnetic concentration of magnetic nanoparticles (MNPs) conjugated with antibodies specific to PVX, 2) MNP aggregates based on gold nanoparticles (GNPs). The MNPs conjugates with biotinylated antibodies and GNPs conjugates with streptavidin were synthesized to realize these approaches. The LFIA with double enhancement (LOD 0.25 ng/mL) was found out to be 32-fold more sensitive compared to LFIA without enhancement (LOD 8 ng/mL). The developed LFIA with double enhancement was effective for the detection PVX in leaf extracts and for the quantitative analysis results from 0.25 to 125 ng/mL (based on the densitometry of line colouration).