Rapid and precise methods to ascertain the presence of viruses are needed for clinical and industrial applications. Available methods are currently slow, imprecise, and have limited sensitivity. A silver (Ag) coated nanorod (AgNR) array in combination with surface enhanced raman spectroscopy (SERS) have been developed to rapidly detect viruses (30-60 seconds) with enhanced sensitivity and specificity. The AgNR substrate enables unimpeded molecular and structural characterization of viruses. This method provides high sensitivity, in the attomolar region, and exhibits the ability to detect trace levels of virus in material while forgoing manipulation or amplification of the virus. This research shows that SERS may detect molecular signatures from important respiratory RNA and DNA viruses. The viruses studied were Swine Influenza (SIV) and Porcine Respiratory and Reproductive Syndrome (PRRS), in pig oral samples, due to their impact on the pork industry and as a vector for transmission to humans. The AgNR substrate was made using oblique angle deposition (OAD) of Ag and Titanium (Ti) onto a glass backing, and polydimethylsiloxane (PDMS) was used to mold wells to hold the viruses on the substrate. Results were analyzed using principle component analysis. Polymerase chain reaction was used to confirm the presence of the viruses in the oral samples. The results show that SERS is able to provide real-time, direct, and rapid detection of viruses providing a link between the limited sensitivity of the available bioassays and the need for more rapid and sensitive detection of infectious viral agents.
Christopher M. Jabczynski, University of Arizona