Low-Voltage Origami-Paper-Based Electrophoretic Device for Rapid Protein Separation

Abstract

We present an origami paper-based electrophoretic device (oPAD-Ep) that achieves rapid (∼5 min) separation of fluorescent molecules and proteins. Due to the innovative design, the required driving voltage is just ∼10 V, which is more than 10 times lower than that used for conventional electrophoresis. The oPAD-Ep uses multiple, thin (180 μm/layer) folded paper layers as the supporting medium for electrophoresis. This approach significantly shortens the distance between the anode and cathode, and this, in turn, accounts for the high electric field (>1 kV/m) that can be achieved even with a low applied voltage. The multilayer design of the oPAD-Ep enables convenient sample introduction by use of a slip layer as well as easy product analysis and reclamation after electrophoresis by unfolding the origami paper and cutting out desired layers. We demonstrate the use of oPAD-Ep for simple separation of proteins in bovine serum, which illustrates its potential applications for point-of-care diagnostic testing.

Low-voltage paper isotachophoresis device for DNA focusing

“…After 4 min, however, the NFT concentration step is replaced by a trapezoidal distribution: a linear increase from Layer 1 to 7, a plateau from Layer 7 to 10, and finally a decrease at Layer 11. This unusual distribution is mainly caused by the mobility differences of the NFT in the paper medium and in free solution, 3 which determines the value of C NFT near the paper/reservoir boundary (boundary effect). As shown in Figure 4b, accumulation of NFT is observed near the right paper/reservoir boundary, due to larger influx of NFT from that reservoir into the paper.…”

“…The fabrication of the o PAD-ITP is similar to that of a related electrophoretic device we have reported previously, 3 but there are some important differences. What man grade 1 cellulose paper (~180 µm thick) was patterned with wax (CorelDRAW designs shown in Figure S1) using a Xerox ColorQube 8750DN inkjet printer.…”

“…3 In the present paper, we adapted this design for ITP, and specifically for ITP concentration of DNA. We report on four specific experiments.…”

Faradaic Ion Concentration Polarization on a Paper Fluidic Platform

“…A variety of creative approaches for preconcentration have been reported for use with conventional glass and plastic microfluidic devices, 16,17 but analogous reports for use with paper-based devices are more limited. 18−22 …”

Paper-Based Flow Fractionation System Applicable to Preconcentration and Field-Flow Separation

“…12 Luo et al suggested an electrophoretic separation device by stacking paper layers. 13 However, these devices provide only transient performance while continuous-flow operations have been desired with conventional microfluidic devices 14,15 because a steady operation is advantageous for reliable sensing by biological, chemical, or electrical reactions at a specific region. 16 Difficulties in developing µPADs with steady performance stem from the transient characteristic of capillary flow through a porous medium.…”