Simultaneous detection of nucleic acid and protein using gold nanoparticles and lateral flow device

In this work, we present a simple and fast approach for simultaneous detection of nucleic acid and protein using gold nanoparticles (GNPs) and a lateral flow device (LFD). Sandwich-type immunoreactions and DNA hybridizations were performed simultaneously on the LFD by using DNA- and antibody-functionalized GNPs. The captured GNPs, due to the DNA hybridization and immunoreaction events on the LFD, produced characteristic red bands that could be used for the qualitative detections of DNA and/or protein. The proof of principle was demonstrated by using 60-mer DNA and rabbit IgG (R-IgG) model targets. The LFD was capable of detecting a minimum of 0.5 nM target DNA and 2 ng mL(-1) IgG simultaneously in 15 min. The proposed LFD shows great promise for in-field and point-of-care testing of disease-related circulating nucleic acid and protein biomarkers in biological fluids.