Rapid Escherichia coli Trapping and Retrieval from Bodily Fluids via a Three-Dimensional Bead-Stacked Nanodevice

Abstract

A novel micro- and nanofluidic device stacked with magnetic beads has been developed to efficiently trap, concentrate, and retrieve Escherichia coli (E. coli) from the bacterial suspension and pig plasma. The small voids between the magnetic beads are used to physically isolate the bacteria in the device. We used computational fluid dynamics, three-dimensional (3D) tomography technology, and machine learning to probe and explain the bead stacking in a small 3D space with various flow rates. A combination of beads with different sizes is utilized to achieve a high capture efficiency (∼86%) with a flow rate of 50 μL/min. Leveraging the high deformability of this device, an E. coli sample can be retrieved from the designated bacterial suspension by applying a higher flow rate followed by rapid magnetic separation. This unique function is also utilized to concentrate E. coli cells from the original bacterial suspension. An on-chip concentration factor of ∼11× is achieved by inputting 1300 μL of the E. coli sample and then concentrating it in 100 μL of buffer. Importantly, this multiplexed, miniaturized, inexpensive, and transparent device is easy to fabricate and operate, making it ideal for pathogen separation in both laboratory and point-of-care settings.

Current and Perspective Diagnostic Techniques for COVID-19

“… 44 The 3D nanostructure has a high surface-to-volume ratio and well-controlled shape factors for virus and nucleic acid capture. 45 Previously, a bead-stacked nanodevice has been developed for pathogen trapping 46 and micropillar polydimethylsiloxane, for rapid viral DNA sensing. 47 Protein nanopore detects viral RNA at the single-molecule level using specific DNA probes.…”

Single Chlamydomonas reinhardtii cell separation from bacterial cells and auto‐fluorescence tracking with a nanosieve device

“…This high resistance presented in the blocked channel is responsible for the high air flow rate measured by the detector of the pressure control system. Furthermore, this type of extremely low aspect ratio nanodevice can be further used for microparticle and pathogen separation and reconfigurable optofluidics [29,40]. As many channels can be patterned on a single chip, the channels can all be tested in parallel to increase the throughput.…”

“…A deformable nanosieve device was previously introduced that can selectively trap microparticles by controlling the hydrodynamic deformation of the shallow channel [28,29]. The height of the channel changes based on the flow rate of the solution applied since the channel deforms under hydrodynamic pressure [28].…”

Single Chlamydomonas reinhardi (C. reinhardtii) cell separation from bacterial cells and auto-fluorescence tracking with a nano-sieve device

“…2d , without roof collapsing, the measured air flow pressure is as low as 2.3 sccm, indicating very low resistance built in the channel. This type of extremely low aspect ratio nano-device can be further used for microparticle and pathogen separation (Chen et al, 2020), droplet microfluidics (Ying et al, 2013), and reconfigurable optofluidics (Brennan et al, 2009).…”

“…We previously introduced a deformable nano-sieve device that can selectively trap microparticles by controlling the hydrodynamic deformation of the shallow channel (Chen et al, 2019; Chen et al, 2020). Furthermore, the captured targets can be easily released by inducing a large deformation of the adaptable channel roof.…”