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Solid-state nanopores can be used to detect nucleic acid structures at the single molecule level. An e-beam has been used to fabricate nanopores in silicon nitride and silicon dioxide membranes, but the pore formation kinetics, and hence its final structure, remain poorly understood. With the aid of high-resolution TEM imaging as well as TEM tomography we(More)
Flagellated bacteria have been employed as microactuators in low Reynolds number fluidic environments. SU-8 microstructures have been fabricated and released on the surface of swarming Serratia marcescens, and the flagella propel the structures along the swarm surface. Phototactic control of these structures is demonstrated by exposing the localized regions(More)
To gain a more thorough understanding of the dynamics of swarming bacteria, a nonlabeled cell tracking algorithm was used to study the velocity field of flagellated bacteria, Serratia marcescens, swarming on a soft agar plate. The average velocities for local regions regularly arranged over the entire flow field were investigated. The velocity field of the(More)
A biomimetic, microscale system using the mechanics of swimming bacteria has been fabricated and controlled in a low Reynolds number fluidic environment. The microswimmer consists of a polystyrene microbead conjugated to a magnetic nanoparticle via a flagellar filament using avidin-biotin linkages. The flagellar filaments were isolated from the bacterium,(More)
Nanometer-sized pores can be used to detect and characterize biopolymers, such as DNA, RNA, and polypeptides, with single-molecule resolution. Experiments performed with the 1.5 nm pore a-hemolysin (a-HL) [1] demonstrated that single-stranded DNA and RNA molecules can be electrophoretical-ly threaded through a pore, and that the ion current flowing through(More)
We demonstrate that flagellated bacteria can be utilized in surface arrays (carpets) to achieve mixing in a low-Reynolds number fluidic environment. The mixing performance of the system is quantified by measuring the diffusion of small tracer particles. We show that the mixing performance responds to modifications to the chemical and thermal environment of(More)
Single molecule methods have provided a significantly new look at the behavior of biomolecules in both equilibrium and non-equilibrium conditions. Most notable are the stretching experiments performed by atomic force microscopes and laser tweezers. Here we present an alternative single molecule method that can unfold a protein domain, observed at electric(More)
We describe a novel approach for optically detecting DNA translocation events through an array of solid-state nanopores that potentially allows for ultra high-throughput, parallel detection at the single-molecule level. The approach functions by electrokinetically driving DNA strands through sub micrometer-sized holes on an aluminum/silicon nitride(More)
Transplantation of insulin-secreting pancreatic islets can provide real-time regulation of blood glucose in patients with type 1 diabetes mellitus. Currently, noninvasive and repetitive monitoring of islet engraftment and function is an emerging and promising modality for successful islet transplantation. Here we report a new technique for highly sensitive(More)