Nonlinear electrical impedance spectroscopy of viruses using very high electric fields created by nanogap electrodes

Abstract

Our living sphere is constantly exposed to a wide range of pathogenic viruses, which can be either known, or of novel origin. Currently, there is no methodology for continuously monitoring the environment for viruses in general, much less a methodology that allows the rapid and sensitive identification of a wide variety of viruses responsible for communicable diseases. Traditional approaches, based on PCR and immunodetection systems, only detect known or specifically targeted viruses. We here describe a simple device that can potentially detect any virus between nanogap electrodes using nonlinear impedance spectroscopy. Three test viruses, differing in shape and size, were used to demonstrate the general applicability of this approach: baculovirus, tobacco mosaic virus (TMV), and influenza virus. We show that each of the virus types responded differently in the nanogap to changes in the electric field strength, and the impedance of the virus solutions differed depending both on virus type and virus concentration. These preliminary results show that the three virus types can be distinguished and their approximate concentrations determined. Although further studies are required, the proposed nonlinear impedance spectroscopy method may achieve a sensitivity comparable to that of more traditional, but less versatile, virus detection systems.

Bio-Impedance Spectroscopy: Basics and Applications

“…The information about completely label-free EIS virus detectors is presented in Refs. [118,119]. To summarize, the EIS-based virus sensing technologies provide a hopeful tool for fighting with various virus diseases like immunodeficiency syndrome, dengue virus-infection, and, highly likely, COVID19.…”

Recent Advances in Electrochemical Immunosensors

“…Marcali and Elbuken exploited an impedimetric detection of agglutinated red blood cells in microdroplets with a droplet-based microfludic system. Yamamoto and co-workers reported on a simple device for the detection of viruses between nanogap electrodes using nonlinear EIS. Depending on the differences in the impedance of virus types and virus concentration in the virus solution, the approach could distinguish and detect their approximate concentrations.…”

Fabrication of a Horizontal and a Vertical Large Surface Area Nanogap Electrochemical Sensor

“…It is well reported that the low-frequency dielectric response is dominated by the ionic relaxation of the buffer [32,41,42,43], complicating detection. The complex composition of the PBS buffer (0.01 M phosphate buffer, 2.7 mM KCl, 0.137 M NaCl) may be the source of this behaviour.…”