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

Hatsuki R, Honda A, Kajitani M, Yamamoto T - Front Microbiol (2015)

Bottom Line: Our living sphere is constantly exposed to a wide range of pathogenic viruses, which can be either known, or of novel origin.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.

View Article: PubMed Central - PubMed

Affiliation: Department of Mechanical and Control Engineering, Tokyo Institute of Technology Tokyo, Japan.

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.

No MeSH data available.


Related in: MedlinePlus

(A) Schematic top view and (B) Cross-sectional view of the measurement device with nanogap electrodes. (C) Scanning ion microscopy image of the measurement region, showing the nanogap electrodes. The gap width is 510 nm.
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Figure 2: (A) Schematic top view and (B) Cross-sectional view of the measurement device with nanogap electrodes. (C) Scanning ion microscopy image of the measurement region, showing the nanogap electrodes. The gap width is 510 nm.

Mentions: Figures 2A,B show top and cross-sectional schematic views of the measurement device. The device is basically fabricated on a quartz substrate patterned with two nanogap electrodes, a polydimethylsiloxane (PDMS) sheet forming the measurement chamber wall, and a glass plate as the chamber lid. The nanogap electrodes were patterned with an Au (250 nm)/Ti (1 nm) layer in strip fabricated by photolithographic lift-off, and the strip was then cut to form opposing electrodes with an intervening nanogap using a focused ion beam (FIB; FB-2200, Hitachi High-Technologies Corp.) (Hatsuki et al., 2013). Figure 2C shows a scanning ion micrograph of the fabricated measurement region. The small grooves in the quartz substrate between and on both sides of the nanogap are overrun regions for cutting the parallel flat-plate electrodes in the FIB process. The fabricated gold/metal electrodes were 250 nm in height and 5 μm in width, with an intervening gap width of 510 nm. The depth of the groove was about 530 nm in the middle of the nanogap. A hole with a diameter of 3 mm was opened in the 0.2-mm-thick PDMS sheet to form the wall of the cell chamber (approximately 1.5 μL volume) and the sheet was then bonded in position to form the measurement cell. For the impedance measurements, the chamber was filled with the sample solution and closed with the glass lid.


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

Hatsuki R, Honda A, Kajitani M, Yamamoto T - Front Microbiol (2015)

(A) Schematic top view and (B) Cross-sectional view of the measurement device with nanogap electrodes. (C) Scanning ion microscopy image of the measurement region, showing the nanogap electrodes. The gap width is 510 nm.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4563260&req=5

Figure 2: (A) Schematic top view and (B) Cross-sectional view of the measurement device with nanogap electrodes. (C) Scanning ion microscopy image of the measurement region, showing the nanogap electrodes. The gap width is 510 nm.
Mentions: Figures 2A,B show top and cross-sectional schematic views of the measurement device. The device is basically fabricated on a quartz substrate patterned with two nanogap electrodes, a polydimethylsiloxane (PDMS) sheet forming the measurement chamber wall, and a glass plate as the chamber lid. The nanogap electrodes were patterned with an Au (250 nm)/Ti (1 nm) layer in strip fabricated by photolithographic lift-off, and the strip was then cut to form opposing electrodes with an intervening nanogap using a focused ion beam (FIB; FB-2200, Hitachi High-Technologies Corp.) (Hatsuki et al., 2013). Figure 2C shows a scanning ion micrograph of the fabricated measurement region. The small grooves in the quartz substrate between and on both sides of the nanogap are overrun regions for cutting the parallel flat-plate electrodes in the FIB process. The fabricated gold/metal electrodes were 250 nm in height and 5 μm in width, with an intervening gap width of 510 nm. The depth of the groove was about 530 nm in the middle of the nanogap. A hole with a diameter of 3 mm was opened in the 0.2-mm-thick PDMS sheet to form the wall of the cell chamber (approximately 1.5 μL volume) and the sheet was then bonded in position to form the measurement cell. For the impedance measurements, the chamber was filled with the sample solution and closed with the glass lid.

Bottom Line: Our living sphere is constantly exposed to a wide range of pathogenic viruses, which can be either known, or of novel origin.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.

View Article: PubMed Central - PubMed

Affiliation: Department of Mechanical and Control Engineering, Tokyo Institute of Technology Tokyo, Japan.

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.

No MeSH data available.


Related in: MedlinePlus