Microfluidic Paper-Based Blood Plasma Separation Device as a Potential Tool for Timely Detection of Protein Biomarkers

Abstract

A current challenge regarding microfluidic paper-based analytical devices (µPAD) for blood plasma separation (BPS) and electrochemical immunodetection of protein biomarkers is how to achieve a µPAD that yields enough plasma to retain the biomarker for affinity biosensing in a functionalized electrode system. This paper describes the development of a BPS µPAD to detect and quantify the S100B biomarker from peripheral whole blood. The device uses NaCl functionalized VF2 filter paper as a sample collection pad, an MF1 filter paper for plasma retention, and an optimized microfluidic channel geometry. An inverted light microscope, scanning electron microscope (SEM), and image processing software were used for visualizing BPS efficiency. A design of experiments (DOE) assessed the device’s efficacy using an S100B ELISA Kit to measure clinically relevant S100B concentrations in plasma. The BPS device obtained 50 μL of plasma from 300 μL of whole blood after 3.5 min. The statistical correlation of S100B concentrations obtained using plasma from standard centrifugation and the BPS device was 0.98. The BPS device provides a simple manufacturing protocol, short fabrication time, and is capable of S100B detection using ELISA, making one step towards the integration of technologies aimed at low-cost POC testing of clinically relevant biomarkers.

A review of Microfluidic blood separation techniques

“…There will be developed interest in the development of new microfluidic devices, optimization of blood separation methods, and integration with other analytical techniques. In addition, the literature indicates that much remains to be explored in this area, including the scalability of microfluidic devices, reproducibility of results, and translation of this technology into clinical settings [9].…”

Paper based microfluidic devices: a review of fabrication techniques and applications

“…This device does not require a membrane to separate the plasma from the whole blood sample and will be helpful in creating POC testing equipment that can identify analytes in small sample quantities. A BPS PAD was created by Burgos et al [ 143 ] to identify and measure the S100B biomarker in peripheral whole blood. The VF2 collecting pad, which conducts vertical and lateral plasma separation was added with the complete blood sample.…”

Rapid Hematocrit Estimation Using a Fold-Crease Induced Fast Flowing Paper Sensor

“…Numerous techniques to control timing and sequence of fluid transport relied primarily on delaying fluid flow, by manipulating channel geometry [8], patterning hydrophobic barriers [9], control and sequential release through reservoirs and valves [10]. However, delaying flow might cause additional concerns of clogging, non-specific absorption and more critically higher evaporative loss and prolong assay time, posing difficulties for rapid and real-time monitoring of biofluids.…”

“…However, certain limitations of paper devices (µPADs) such as fixed pore dimensions and imprecise flow control, could have an impact on the accuracy and reproducibility of certain assays, restricting their utility for on-field testing [6],[7]. Numerous techniques to control timing and sequence of fluid transport relied primarily on delaying fluid flow, by manipulating channel geometry [8], patterning hydrophobic barriers [9], control and sequential release through reservoirs and valves [10]. However, delaying flow might cause additional concerns of clogging, non-specific absorption and more critically higher evaporative loss and prolong assay time, posing difficulties for rapid and real-time monitoring of biofluids.…”