Armin Darvish

Drexel University | DU · School of Biomedical Engineering, Science and Health Systems

DOI: 10.1002/elps.201800476 The cover picture shows how the deformation of nanosized liposome was measured using an automated recapturing platform. The red part of the graph is the current trace while the red liposome translocates through the nanopore from the cis to the trans side with low voltage by electrophoresis. The consecutive blue current t...

DOI: 10.1002/elps.201800311 This cover picture shows how we measured the deformation of virus particle using nanopore sensor. A green virus particle is passing through a nanopore on the gray membrane by the electrophoresis. The virus particle deforms inside the nanopore by the electric field gradient which is represented by the transparent sphere a...

This paper describes a method to gauge the stiffness of nanosized liposomes - a nanoscale vesicle - using a custom-made recapture platform coupled to a solid-state nanopore sensor. The recapture platform electrically profiles a given liposome vesicle multiple times through automated reversal of the voltage polarity immediately following a transloca...

Enveloped viruses fuse with cells to transfer their genetic materials and infect the host cell. Fusion requires deformation of both viral and cellular membranes. Since the rigidity of viral membrane is a key factor in their infectivity, studying the rigidity of viral particles is of great significance in understating viral infection. In this paper,...

In this article, a porous hollow biotemplated nanoscale helix that can serve as a low Reynolds number robotic swimmer is reported. The nanorobot utilizes repolymerized bacterial flagella from Salmonella typhimurium as a nanotemplate for biomineralization. We demonstrate the ability to generate templated nanotubes with distinct helical geometries by...

This paper describes a general approach for transferring clean single-layer graphene onto silicon nitride nanopore devices and the use of the electron beam of a transmission electron microscope (TEM) to drill size-controlled nanopores in freely suspended graphene. Besides nanopore drilling, we also used the TEM to heal and completely close the unwa...

Solid-state nanopores have been widely used in the past for single-particle analysis of nanoparticles, liposomes, exosomes and viruses. The shape of soft particles, particularly liposomes with a bilayer membrane, can greatly differ inside the nanopore compared to bulk solution as the electric field inside the nanopores can cause liposome electrodef...

Solid-state nanopores have gained much attention as a bioanalytical platform. By virtue of their tunable nanoscale dimensions, nanopore sensors can a spatial resolution that spans a wide range of biological species from a single-molecule to a single virus or microorganism. Several groups have already used solid-state nanopores for tag-free detectio...

Membrane deformation of nano-vesicles is crucial in many cellular processes such as virus entry into the host cell, membrane fusion, endo- and exocytosis; however, studying deformation of sub-100 nm soft vesicles is very challenging using the conventional techniques. In this paper, we report detecting co-translocational deformation of individual 1,...

This paper describes microparticle and bacterial translocation studies using low aspect ratio solid state micropores. Micropores, 5 μm in diameter, were fabricated in 200 nm thick free standing silicon nitride membranes, resulting in pores with an extremely low aspect ratio, nominally 0.04. For microparticle translocation experiments, sulfonated po...

This paper reports electron beam induced shrinking of nanopores drilled in free-standing graphene. Nanopores with diameters in the range of 40-60 nm were easily shrunk down to 2 nm and even completely closed by exposure to low beam current densities in a transmission electron microscope (TEM). This method can be used to fine-tune nanopore shape and...