A new biosensor is capable of rapid detection of the H1N1 flu virus, a strain which poses a strong treat for pandemic outbreak. The new sensor, developed by researchers at Tokyo Medical and Dental University, measures small voltage changes in an electrically conductive polymer to identify virus concentrations nearly 100 times smaller than other available sensors.
The polymer behind the sensor
The polymer that is the key to the new sensor is well-suited to the task because the researchers were able to attach biomolecules to it, allowing them to bind with specific targets, such as flu viruses.
In this study, poly(3,4-ethylenedioxythiophene) (PEDOT) was modified with a functional group that binds with the H1N1 human influenza virus, but not avian flu strains.
The researchers explained that conducting polymers have several advantages over inorganic counterparts. Among the advantages are the ability to conduct both electrical and ionic carriers, mechanical flexibility, low cytotoxicity, low-cost production by casting or printing, and tunable properties via chemical synthesis or doping.
How the biosensor works
To construct the biosensor, the polymer film was placed between two electrodes. When a solution containing H1N1, which carries a tiny positive charge on its exterior shell, was added, some of the viruses stuck to the polymer and increased the voltage measured by the electrodes. This electrical method allows the sensor to detect the presence of miniscule amounts of the virus. Viral loads are often measured in hemagglutination units (HAU). The new sensor can detect viral concentrations as small as 0.013 HAU. By comparison, commercially available kits that use immunochromatographic tests only work for concentrations greater than about 1.13 HAU. This represents an almost 100-fold increase in sensitivity.
To learn more about this new flu-detecting biosensor, see the researchers' published findings in Applied Materials & Interfaces.