Jornal de Nanomedicina e Nanotecnologia

Abstrato

A Label-free Aptasensor for Rapid Detection of H1N1 Virus based on Graphene Oxide and Polymerase-aided Signal Amplification

Xinru Feng, Keyi Liu, Yi Ning, Lijuan Chen and Le Deng

Single-stranded DNA aptamers specific to the hemagglutinin (HA) protein of avian influenza virus (A/Puerto Rico/8/1934) were obtained by SELEX process in 13 cycles. The aptamer with the highest affinity and specificity was applied to an affinity bioassay. An aptamer hairpin (aHP) was prepared that consists of two DNA regions, viz. (a) the aptamer for the HA protein and (b) an oligonucleotide designed to form a stem-loop structure. In the absence of target, the aHP maintains its hairpin structure and was adsorbed to the Graphene Oxide (GO). The fluorescence of SYBR Green I (SGI) is almost quenched. On addition of the target, aHP unfolds and the GO is no longer attached but released to the solution. By applying a polymerase elongation reaction, a long dsDNA product is generated when SGI is added. The proposed method could detect HA and H1N1 virus with a limit of 2.5 μg/mL and 1×10² TCID50, respectively. Consequently, this paves the way for influenza virus detection and is employed in basic research and medical diagnosis.