Surface-Enhanced Raman Scattering Identification of Nucleic Acid Targets by Acetylene-Tagged Hoechst Molecule Binding with DNA-Tethered Gold Nanoparticles

Raman probes have been utilized to identify biomolecules. However, their application for nucleic acid sensing remains limited because of the requirement of purification processes. Here, we provide a general purification-free method for the detection of specific nucleic acids based on surface-enhanced Raman scattering (SERS) using functionalized gold nanoparticles. We identified the robust Raman signal of an acetylene-tagged Hoechst molecule (AH) through SERS because of its binding to nanoparticles bearing double-stranded oligodeoxynucleotides on their surface. Once target nucleic acids were added to the system, strand displacement on the particles and dissociation of AH from the particles occurred spontaneously, leading to a dramatic decrease in the signal intensity. We also found that the cellular miRNA level was successfully identified by the system.

Automated summary

In this study, a purification-free method based on surface-enhanced Raman scattering (SERS) using functionalized gold nanoparticles was developed for the detection of specific nucleic acids. The robust Raman signal of an acetylene-tagged Hoechst molecule (AH) was identified through SERS, and the target nucleic acids were detected through strand displacement and dissociation processes.