Aptamer-coated track-etched membranes with a nanostructured silver layer for single virus detection in biological fluids
В. И. Кукушкин, Olga Kristavchuk, Evgeny Andreev, Nadezda Meshcheryakova, Olga V. Zaborova, Alexandra Gambaryan, Alexander Nechaev, Elena Zavyalova
Abstract
Aptasensors based on surface-enhanced Raman spectroscopy (SERS) are of high interest due to the superior specificity and low limit of detection. It is possible to produce stable and cheap SERS-active substrates and portable equipment meeting the requirements of point-of-care devices. Here we combine the membrane filtration and SERS-active substrate in the one pot. This approach allows efficient adsorption of the viruses from the solution onto aptamer-covered silver nanoparticles. Specific determination of the viruses was provided by the aptamer to influenza A virus labeled with the Raman-active label. The SERS-signal from the label was decreased with a descending concentration of the target virus. Even several virus particles in the sample provided an increase in SERS-spectra intensity, requiring only a few minutes for the interaction between the aptamer and the virus. The limit of detection of the aptasensor was as low as 10 viral particles per mL (VP/mL) of influenza A virus or 2 VP/mL per probe. This value overcomes the limit of detection of PCR techniques (∼10 3 VP/mL). The proposed biosensor is very convenient for point-of-care applications.