Tunable Electrophoretic Separations Using a Scalable, Fabric-Based Platform

Abstract

There is a rising need for low-cost and scalable platforms for sensitive medical diagnostic testing. Fabric weaving is a mature, scalable manufacturing technology and can be used as a platform to manufacture microfluidic diagnostic tests with controlled, tunable flow. Given its scalability, low manufacturing cost (<$0.25 per device), and potential for patterning multiplexed channel geometries, fabric is a viable platform for the development of analytical devices. In this paper, we describe a fabric-based electrophoretic platform for protein separation. Appropriate yarns were selected for each region of the device and weaved into straight channel electrophoretic chips in a single step. A wide dynamic range of analyte molecules ranging from small molecule dyes (<1 kDa) to macromolecule proteins (67-150 kDa) were separated in the device. Individual yarns behave as a chromatographic medium for electrophoresis. We therefore explored the effect of yarn and fabric parameters on separation resolution. Separation speed and resolution were enhanced by increasing the number of yarns per unit area of fabric and decreasing yarn hydrophilicity. However, for protein analytes that often require hydrophilic, passivated surfaces, these effects need to be properly tuned to achieve well-resolved separations. A fabric device tuned for protein separations was built and demonstrated. As an analytical output parameter for this device, the electrophoretic mobility of a sedimentation marker, Naphthol Blue Black bovine albumin in glycine-NaOH buffer, pH 8.58 was estimated and found to be -2.7 × 10(-8) m(2) V(-1) s(-1). The ability to tune separation may be used to predefine regions in the fabric for successive preconcentrations and separations. The device may then be applied for the multiplexed detection of low abundance proteins from complex biological samples such as serum and cell lysate.

Thread based electrofluidic platform for direct metabolite analysis in complex samples

“…Hydrophilic threads do not require external forces to transport aqueous fluids and most threads are flexible and thus can be easily incorporated or woven into various textile supports. Additionally, threads can be readily disposed of after use, are readily mass produced, and easily functionalised, coated or extruded in varying formats, from a wide variety of starting materials, both natural and synthetic [2][3][4][5][6][7][8][9][10][11][12][13]. Due to this simplicity and functionality, a variety of applications have been demonstrated using two main platforms over the last few years.…”

“…The second group are based upon single threads, which generally involve much smaller solution volumes, as in these examples the flow within the strands of the thread is confined to one direction. The use of this later platform has been applied to bacteria isolation and quantification [24], chemotaxis studies for cell culture systems [25], immunoassays [26,27], blood typing [28], chemical synthesis [29], and the determination of nucleic acids [30,31], proteins [4,7,29,[31][32][33][34], glucose [29,[35][36][37], drugs [38], small ions [6,8,32,39] and metals [40]. Several detection techniques have been used for these various applications, with the most common, albeit the least sensitive, being simple colorimetric detection.…”

A low-cost, ultraflexible cloth-based microfluidic device for wireless electrochemiluminescence application

“…(2) The choice of paper in μPADs seems to be too narrow. Cloth has a strong mechanical strength due to its hierarchical structure, displays better wicking and mixing mechanisms compared to its paper counterpart [6], possesses high flexibility, shows ease in creating 3D structures [6,7], and exhibits simplicity of integrating with thread-based materials [8][9][10][11]. (4) Paper has usually relatively less interstitial spaces.…”

“…We and others have developed several fabrication methods for μCADs, including weaving [8,9,11,12], cutting [13], batik painting [6,7,14,15], stereo-stitching [10], wax screen-printing [16][17][18], and photolithography [19][20][21][22][23]. Cloth is a viable material for the development of analytical devices due to its low material and manufacture costs, ability to wick assay fluids by capillary forces, and potential for patterning multiplexed channel geometries.…”

“…We and others have developed several fabrication methods for μCADs, including weaving [8,9,11,12], cutting [13], batik painting [6,7,14,15], stereo-stitching [10], wax screen-printing [16][17][18], and photolithography [19][20][21][22][23]. We and others have developed several fabrication methods for μCADs, including weaving [8,9,11,12], cutting [13], batik painting [6,7,14,15], stereo-stitching [10], wax screen-printing [16][17][18], and photolithography [19][20][21][22][23].…”