Electrical detection of single viruses

TLDR

The study demonstrates direct, real‑time electrical detection of single virus particles with high selectivity using nanowire field‑effect transistors. Simultaneous electrical and optical measurements confirm that conductance changes arise from single‑virus binding and unbinding at the nanowire surface. Antibody‑functionalized nanowire arrays produced distinct conductance spikes for influenza A, confirmed by optical tracking, and pH studies revealed a field‑effect mechanism enabling rapid isoelectric point determination and kinetic analysis; the platform also permits parallel detection of multiple virus types and suggests scalable integration for high‑throughput single‑virus surveillance.

Abstract

We report direct, real-time electrical detection of single virus particles with high selectivity by using nanowire field effect transistors. Measurements made with nanowire arrays modified with antibodies for influenza A showed discrete conductance changes characteristic of binding and unbinding in the presence of influenza A but not paramyxovirus or adenovirus. Simultaneous electrical and optical measurements using fluorescently labeled influenza A were used to demonstrate conclusively that the conductance changes correspond to binding/unbinding of single viruses at the surface of nanowire devices. pH-dependent studies further show that the detection mechanism is caused by a field effect, and that the nanowire devices can be used to determine rapidly isoelectric points and variations in receptor-virus binding kinetics for different conditions. Lastly, studies of nanowire devices modified with antibodies specific for either influenza or adenovirus show that multiple viruses can be selectively detected in parallel. The possibility of large-scale integration of these nanowire devices suggests potential for simultaneous detection of a large number of distinct viral threats at the single virus level.