Oligonucleotide-linked gold nanoparticle aggregates for enhanced sensitivity in lateral flow assays†
Lateral flow assays (LFAs) as rapid analytical techniques promise to be widely used in point-of-care (POC) diagnostics because of their affordability and simplicity. However, LFAs still suffer from low sensitivity in detection of various biomarkers, e.g., nucleic acids. In this study, we developed a simple and general one-step signal amplification strategy, which employed oligonucleotide-linked gold nanoparticle (AuNP) aggregates to enhance the sensitivity in nucleic acid lateral flow (NALF) assays. Using a nucleic acid sequence of human immunodeficiency virus type 1 (HIV-1) as a model analyte, we observed that the detection limit of the developed NALF assay was 0.1 nM, which was improved by 2.5-fold compared with that of a non-signal amplification approach. The methodology described here could be used to detect a broad range of nucleic acids, and the general signal amplification approach could be potentially adopted in other types of LFAs.