Label-Free Capacitance-Based Identification of Viruses

By Mahmoud Al Ahmad, Farah Mustafa, Lizna M. Ali, Jimsheena V. Karakkat & Tahir A. Rizvi
Published in Scientific Reports NULL 2015

Abstract

This study was undertaken to quantitate a single virus suspension in culture medium without any pre-processing. The electrical capacitance per virus particle was used to identify the kind of virus present by measuring the suspension (virus plus medium) capacitance, de-embedding the medium contribution, and dividing by the virus count. The proposed technique is based on finding the single virus effective dielectric constant which is directly related to the virus composition. This value was used to identify the virus type accordingly. Two types of viruses thus tested were further quantified by a biochemical technique to validate the results. Furthermore, non-organic nanoparticles with known concentration and capacitance per particle were identified using the proposed method. The selectivity of the method was demonstrated by performing electrical measurements on a third virus, revealing that the proposed technique is specific and sensitive enough to permit detection of a few hundred virus particles per milliliter within a few minutes.The electrical measurements were performed by loading different virus suspensions inside an open-ended coaxial cable and the electrical measurements were achieved using the Gamry 3000 instrument (USA) that has a wide range of electrical measurement capabilities.

Read Article » Back