Plasmonic Coupling Interference: a new approach for cancer diagnostics using SERS detection

Abstract

We have developed a novel label-free approach referred to as plasmonic coupling interference (PCI) nanoprobes for nucleic acid detection using surface-enhanced Raman scattering (SERS). To induce a strong plasmonic coupling effect and SERS signal, a nano-network of silver nanoparticles having the Raman label located between adjacent nanoparticles is assembled by Raman-labeled nucleic acid duplexes. The PCI method then utilizes specific nucleic acid sequences of interest as competitor elements of the Raman-labeled DNA probes to interfere the formation of the nucleic acid-crosslinked nano-networks in a competitive binding process, resulting in a reduced SERS signal. We illustrate the potential of the PCI technique for biomedical applications by detecting single-nucleotide polymorphism (SNP) and microRNA sequences involved in breast cancers. The results of this study could lead to the development of nucleic acid diagnostic tools for biomedical diagnostics and biosensing applications using SERS detection.