Single and double stranded DNA detection using locked nucleic acid (LNA) functionalized nanoparticles

Gold and silver nanoparticles functionalized with oligonucleotides can be used for the detection of specific sequences of DNA. We show that gold nanoparticles modified with locked nucleic acid (LNA) form stronger duplexes with a single stranded DNA target and offer better discrimination against single base pair mismatches than analogous DNA probes. Our LNA nanoparticle probes have also been used to detect double stranded DNA through triplex formation, whilst still maintaining selectivity for only complementary targets. Nanoparticle conjugates embedded with suitable surface enhanced resonance Raman scattering (SERRS) labels have been synthesized enabling simultaneous detection and identification of multiple DNA targets.