AUTHOR=Zhdanov Gleb , Nyhrikova Ekaterina , Meshcheryakova Nadezda , Kristavchuk Olga , Akhmetova Assel , Andreev Evgeny , Rudakova Elena , Gambaryan Alexandra , Yaminsky Igor , Aralov Andrey , Kukushkin Vladimir , Zavyalova Elena 

TITLE=A Combination of Membrane Filtration and Raman-Active DNA Ligand Greatly Enhances Sensitivity of SERS-Based Aptasensors for Influenza A Virus

JOURNAL=Frontiers in Chemistry

VOLUME=Volume 10 - 2022

YEAR=2022

URL=https://www.frontiersin.org/journals/chemistry/articles/10.3389/fchem.2022.937180

DOI=10.3389/fchem.2022.937180

ISSN=2296-2646

ABSTRACT=Biosensors combining the ultrahigh sensitivity of surface-enhanced Raman scattering (SERS) and specificity of nucleic acid aptamers have recently drawn attention in the detection of respiratory viruses. The most sensitive SERS-based aptasensors allow determining as low as 10^4 virus particles per mL that is 100-fold lower than antibody-based lateral flow tests but 10-100-times higher than routine polymerase chain reaction with reversed transcription (RT-PCR). Sensitivity of RT-PCR has not been achieved in SERS-based aptasensors despite the usage of sophisticated SERS-active substrates. Here we proposed a novel design of SERS-based aptasensor with the limit of detection of just 10^3 particles per mL of influenza A virus that approaches closely to RT-PCR sensitivity. The sensor utilizes silver nanoparticles with the simplest preparation instead of sophisticated SERS-active surfaces. The analytical signal is provided by a unique Raman-active dye that competes with the virus for the binding to the G-quadruplex core of the aptamer. The aptasensor functions even with aliquots of the biological fluids due to separation of the off-target molecules by pre-filtration through polymeric membrane. The aptasensor detected influenza viruses in the range of 1·10^3 – 5·10^10 virus particles per mL.