Self-driven filter-based blood plasma separator microfluidic chip for point-of-care testing

Abstract

Abstract:Recently, there is a growing need for lab-on-a-chip devices in clinical analysis and diagnostics especially near the patient care. First step, in the most blood assays is plasma extraction from whole blood. This paper presents a novel high throughput blood plasma separation microfluidic chip, which with just a single droplet of undiluted human blood (~5µL) can separate (more than 0.1µL) plasma from whole blood without the need of external forces with high purity (more than 98%) and reasonable time (3 to 5 minutes). This would be the first step towards the realization of single use, self-blood test which does not require any external forces or connection to deliver and analyze a fresh whole blood sample in contrast to the conventional blood analysis which have variable waiting times. Polydimethylsiloxane (PDMS) is utilized as the base material to manufacture the microchip due to its biocompatibility and outstanding characteristics. PDMS has been modified with a strong nonionic surfactant (Silwet L-77) to achieve a hydrophilic behavior. The main advantage of this microfluidic chip design is the clogging delay on the filtration area, which results in an increased amount of extracted plasma (0.1 µL). Moreover, the plasma can be collected in one or more 10-µm-depth channels to facilitate the detection and readout of multiple blood assays. This high volume of extracted plasma is achieved; thanks to a novel design that combines the maximum pumping efficiency without disturbing the red blood cells (RBCs) trajectory by the use of different hydrodynamic principles such as constriction effect and symmetrical filtration mode. To demonstrate the microfluidic chip functionality, a novel hybrid microdevice, exhibiting the benefits of both microfluidics and lateral flow Immuno-chromatographic tests, is designed and fabricated. The performance of the presented hybrid microdevice is validated utilizing rapid detection of the thyroid stimulating hormone (TSH) within a single droplet of whole blood. ABSTRACTRecently, there is a growing need for lab-on-a-chip devices in clinical analysis and diagnostics especially near the patient care. First step, in the most blood assays is plasma extraction from whole blood. This paper presents a novel high throughput blood plasma separation microfluidic chip, which with just a single droplet of undiluted human blood (~5µL) can separate (more than 0.1µL) plasma from whole blood without the need of external forces with high purity (more than 98%) and reasonable time (3 to 5 minutes). This would be the first step towards the realization of single use, self-blood test which does not require any external forces or connection to deliver and analyze a fresh whole blood sample in contrast to the conventional blood analysis which have variable waiting times. Polydimethylsiloxane (PDMS) is utilized as the base material to manufacture the microchip due to its biocompatibility and outstanding characteristics. PDMS has been modified with a strong nonionic surfactant (Silwet L-77) to achieve a hydro...

Microfluidic point-of-care blood panel based on a novel technique: Reversible electroosmotic flow

“…The proposed microfluidic device is based on a microfluidic blood plasma filter developed in our group, 16,25 see Fig. 1(a).…”

“…1(a). In our previous work, Madadi et al 16 the cross-flow filtration and capillarity were used for blood plasma separation but the clogging phenomena limited the plasma extracted (0.1 ll), see Fig. 1(b).…”

“…16 has been modified to allocate precisely the test strip, see Fig. 3 where steps (a) till (d), for Microchannel Integrated Micro-Pillars (MIMP) fabrication are used in Ref.…”

“…3 where steps (a) till (d), for Microchannel Integrated Micro-Pillars (MIMP) fabrication are used in Ref. 16 and steps (e) to (h) has been added. Conventional photolithography and soft lithography procedures have been utilized to generate top part (Polydimethylsiloxane (PDMS) microchannel) ( Fig.…”

“…[9][10][11] The cross flow filtration method has demonstrated its outstanding properties to separate particles from a suspension, [12][13][14][15] but its major drawback is the clogging of the filtration area, which was solved either increasing the sample dilution 12,13 or pumping at low flow rates. 15 In our previous work, Madadi et al 16 the blood plasma separation used cross-flow filtration and capillarity. But after a while, the blood flow velocity in the transport channel was slowed down, which leads to an accumulation of cells in the entrance of the separation area (red blood cells (RBCs) clogging), see Fig.…”