SERS-based DNA Sensors Using Morpholino Oligos

In this study we compare binding efficiencies of morpholino probes under 1.0M and 0.01M salt concentrations and examine DSNB-conjugated gold nanoparticles with silica-coated magnetic nanoparticles for use in SERS-based nucleic acid biosensors using morpholinos. Advancements in Surface Enhanced Raman Spectroscopy (SERS) have made possible devices capable of sensing a particular sequence of DNA in minutes. Applications of these devices include rapid identification of disease, possibly before symptoms arise. If practical use of such sensors is obtained, many false diagnoses could potentially be avoided. Equimolar solutions of target DNA and morpholino probes were prepared and biding efficiencies of morpholino-DNA were compared. Conjugated Gold and magnetic nanoparticles were exposed to two sequences of DNA; one being the target West Nile Virus (WNV) DNA and the other being Blue Tongue Virus DNA. Both DNA solutions were analyzed using SERS spectroscopy. We found that morpholino probes bind more efficiently at low salt concentrations. We demonstrated proof of concept of our DNA sensing method; however, future studies will be required to optimize this sensing protocol.