Enhanced lateral flow assay with double conjugates for the detection of exosomes

Abstract

Exosomes are promising biological biomarkers for monitoring a number of diseases, especially cancers. Here, we developed a double gold nanoparticles (GNPs) conjugates based lateral flow assay (D-LFA) for rapidly and sensitively detecting and molecular profiling of exosomes. Based on these two GNPs conjugates, the signal amplification can be achieved without any additional operation. The antibody on the 1st GNPs conjugate could recognize exosomes and form a sandwich format on the test zone. The 2nd GNPs conjugate was designed to bind to the 1st GNPs conjugate to realize signal amplification. This biosensor enabled visual and quantitative detection of exosomes by the accumulation of GNPs on the test zone and showed a low detection limit of 1.3×103 particles/μL, which has been improved 13-fold compared with the normal lateral flow assay. The D-LFA exhibited good sensitivity and reproducibility and has been successfully used for the detection of exosomes in fetal bovine serum, which proved its potential application in practical diagnostics.