One dimensional zinc oxide nanostructures assisted paper-based blood-plasma separation

Low-cost, paper-based platforms are gaining increasing relevance in modern diagnostics and biosensing. Most diagnostic systems using blood samples require blood-plasma separation to reduce complexity and achieve better results. Blood plasma separation is often carried-out by using various membrane based filters. This paper presents a new method for capturing red blood cells on Whatman filter paper with no. 1, 2, 5 and glass fiber discs. All four paper types were subjected to modification with hydrothermally grown zinc oxide nanorods. Growth and morphologies of zinc oxide nanorods were confirmed by SEM, XRD and XPS studies. The blood plasma separation experiments were done by cutting the papers into identical strips with dimension of 5 × 20 mm2. 3 μL of blood was mixed with equal volume of antibody solution and pipetted on each strip. The colored antibody solution was used to track the path of antibody, eventually the separated plasma. The dried strips were scanned and the difference in the distance travelled by colored solution of antibodies was measured. From the results, it is clear that all four paper strips covered with nanorods have shown more distance travelled and better separation than their control samples.