Electrical detection of norovirus capsid using dielectrophoretic impedance measurement method

In this work, we demonstrated an electrical detection technique of norovirus capsid in liquid by using dielectrophoretic impedance measurement (DEPIM). DEPIM is a method composing of capturing target particles by dielectrophoresis (DEP) in the gap of microelectrodes and measuring the impedance change of the microelectrodes caused by the captured particles. DEPIM has been successfully applied to bacteria detection by the present authors. This is the first report to extend scope of DEPIM inspection from bacteria to norovirus. Recombinant norovirus capsid was employed as target particles in experiments due to safety concerns. First, we showed virus capturing by DEP using fluorescent labeled norovirus capsid. Then, DEPIM of the capsid was carried out. As the result, DEPIM detected 2.5 ng/ml of the norovirus capsid in 300 sec. This implies that DEPIM has comparable sensitivity but shorter detection time than immunochromatography.