Blood separation on microfluidic paper-based analytical devices

Abstract

A microfluidic paper-based analytical device (μPAD) for the separation of blood plasma from whole blood is described. The device can separate plasma from whole blood and quantify plasma proteins in a single step. The μPAD was fabricated using the wax dipping method, and the final device was composed of a blood separation membrane combined with patterned Whatman No.1 paper. Blood separation membranes, LF1, MF1, VF1 and VF2 were tested for blood separation on the μPAD. The LF1 membrane was found to be the most suitable for blood separations when fabricating the μPAD by wax dipping. For blood separation, the blood cells (both red and white) were trapped on blood separation membrane allowing pure plasma to flow to the detection zone by capillary force. The LF1-μPAD was shown to be functional with human whole blood of 24-55% hematocrit without dilution, and effectively separated blood cells from plasma within 2 min when blood volumes of between 15-22 μL were added to the device. Microscopy was used to confirm that the device isolated plasma with high purity with no blood cells or cell hemolysis in the detection zone. The efficiency of blood separation on the μPAD was studied by plasma protein detection using the bromocresol green (BCG) colorimetric assay. The results revealed that protein detection on the μPAD was not significantly different from the conventional method (p > 0.05, pair t-test). The colorimetric measurement reproducibility on the μPAD was 2.62% (n = 10) and 5.84% (n = 30) for within-day and between day precision, respectively. Our proposed blood separation on μPAD has the potential for reducing turnaround time, sample volume, sample preparation and detection processes for clinical diagnosis and point-of care testing.

Bubble-free and pulse-free fluid delivery into microfluidic devices

“…Microfluidic devices, which have distinctive advantages over conventional methods, have been successfully demonstrated for various applications in drug delivery, [1][2][3][4][5] accurate dispensing, 6 analytical devices, [7][8][9] clinical diagnostics, [10][11][12][13] point-of-care-testing, 14,15 and cell studies. [16][17][18] Based on fluid transport in microfluidic channels, the microfluidic devices can achieve their unique functions such as manipulation, [19][20][21][22] mixing, [23][24][25] and analysis.…”

A paper-based microfluidic biosensor integrating zinc oxide nanowires for electrochemical glucose detection

“…One can see that the sensitivities and LODs provided by our devices are superior to the commercial glucose meters and the previously reported EμPADs 3,5,19 . Although we used human serum rather than whole blood in this work, it is totally feasible to integrate a layer of filtering paper/membrane on top of the device's reaction zone to filter out blood cells 26 . The above results prove the effectiveness of our ZnO-NW EμPADs for the detection of glucose in real blood samples.…”

Paper and Fiber-Based Bio-Diagnostic Platforms: Current Challenges and Future Needs

“…High throughput systems incorporated into the paper-based devices have automated the separation step by using a diverse range of solid materials, including beads, microparticles, fiber matrices, and coated tubes and plates [147,[156][157][158][159][160][161][162][163]. Additionally, application of pre-depositing agglutination antibodies, concentrated salt solution for blood cell deformation and filtering via paper pores using capillary force are known to be effective techniques for sample separation [164][165][166].…”