A portable impedance biosensor for detection of multiple avian influenza viruses

A microelectrode array-based impedance biosensor was developed and demonstrated for rapid, specific, sensitive detection of multiple avian influenza viruses (AIVs). Six interdigitated microelectrodes were placed at the bottom of six wells in a microplate to form six sensors for different AIVs and controls. Then, AIV specific ligands were immobilized on the microelectrode surface to capture target viruses. To enhance the sensitivity, AIV specific aptamers conjugated gold nanoparticles and thiocyanuric acid were employed to form a network structure and used as an amplifier. For impedance measurement, a laptop with LabVIEW software was used to generate excitation signals at different frequencies with an audio card and measure the impedance of target viruses through a data acquisition card. The developed biosensor was portable with the sensitivity and specificity for applications to on-site or in-field rapid screening of AIVs.