Abstract
In this research a DNA aptamer, which was selected through SELEX (systematic evolution of ligands by exponential enrichment) to be specific against the H5N1 subtype of the avian influenza virus (AIV), was used as an alternative reagent to monoclonal antibodies in an impedance biosensor utilizing a microfluidics flow cell and an interdigitated microelectrode for the specific detection of H5N1 AIV. The gold surface of the interdigitated microelectrode embedded in a microfluidics flow cell was modified using streptavidin. The biotinylated aptamer against H5N1 was then immobilized on the electrode surface using biotin–streptavidin binding. The target virus was captured on the microelectrode surface, causing an increase in impedance magnitude. The aptasensor had a detection time of 30 min with a detection limit of 0.0128 hemagglutinin units (HAU). Scanning electron microscopy confirmed the binding of the target virus onto the electrode surface. The DNA aptamer was specific to H5N1 and had no cross-reaction to other subtypes of AIV (e.g., H1N1, H2N2, H7N2). The newly developed aptasensor offers a portable, rapid, low-cost alternative to current methods with the same sensitivity and specificity.
Highlights
The H5N1 subtype of the avian influenza virus (AIV) has caused the most lethal outbreaks of highly pathogenic avian influenza (HPAI) in poultry and fatal infections in human cases for over a decade
This study suggested that aptamers have added advantages when used in impedance biosensors in that their small size and uniformity result in low noise and high repeatability
The second non-Faradic biosensor developed for the detection of H5N1 AIV used immunomagnetic separation with anti-H5 antibody-coated magnetic nanobeads, a microfluidic flow cell with an embedded interdigitated microelectrode that was coated in anti-N1 antibody and chicken red blood cell (RBC) labels for amplification [34]
Summary
The H5N1 subtype of the avian influenza virus (AIV) has caused the most lethal outbreaks of highly pathogenic avian influenza (HPAI) in poultry and fatal infections in human cases for over a decade. The second non-Faradic biosensor developed for the detection of H5N1 AIV used immunomagnetic separation with anti-H5 antibody-coated magnetic nanobeads, a microfluidic flow cell with an embedded interdigitated microelectrode that was coated in anti-N1 antibody and chicken red blood cell (RBC) labels for amplification [34] This biosensor was capable of detecting H5N1 AIV at 103 EID50·mL−1 but had a detection time of 2 h and required multiple steps in the detection protocol. An impedance-based aptasensor was developed for the detection of H5N1 AIV with enhanced sensitivity [38] This reported method required signal amplification with labels, and the detection time was prolonged to 2 h. It overcame several disadvantages from the previous biosensors, namely long electrode preparation time and reliance on nanoparticles or biolabels
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
