Nano/Microfluidics for diagnosis of infectious diseases in developing countries

Abstract

Nano/Microfluidic technologies are emerging as powerful enabling tools for diagnosis and monitoring of infectious diseases in both developed and developing countries. Miniaturized nano/microfluidic platforms that precisely manipulate small fluid volumes can be used to enable medical diagnosis in a more rapid and accurate manner. In particular, these nano/microfluidic diagnostic technologies are potentially applicable to global health applications, since they are disposable, inexpensive, portable, and easy-to-use for detection of infectious diseases. In this paper, we review recent advances in nano/microfluidic technologies for clinical point-of-care applications at resource-limited settings in developing countries.

Figure 1

A schematic of a platform for POC diagnostics in developing and developed countries. The device shown above was selected as a representative example of a wireless data-reading platform for global health. The image of the device was reprinted from Ref [3] by permission of Annual Reviews.

Figure 2

On-chip microfluidic approaches. (a) CCD-based imaging platform with a disposable microfluidic device (top) and the CCD shadow image of CD4⁺ T-lymphocytes captured in the microfluidic device (bottom). Scale bar is 100 μm. (b) Phase contrast and fluorescent images to identify captured cells: (i) Phase contrast image of cells, (ii) DAPI stained cells, (iii) CD4⁺/AF488 stained cells, (iv) CD3⁺/AF647 stained cells. Modified from Ref [22] with permission from the Royal Society of Chemistry. (c) Photograph of a mass-producible device and a bright field image of the expansion channel at the detection zone (top and middle) and intensity profile of fluorescence of particles flowing through the expansion geometry (bottom). Reprinted from Ref [46] with permission from the Royal Society of Chemistry.

Figure 3

Schematic of the lateral flow strip chip to diagnose malaria. (Top) Device preparation with nitrocellulose strip, (middle) Operation principle of a lateral flow strip chip, and (bottom) Expected results of a lateral flow strip. Reprinted from Ref [86] with permission from Nature Publishing.

Figure 4

Microfluidic NMR biosensor combined with magnetic nanoparticles for potential applications of TB test in resource-limited settings. (a) Principle of proximity assay using magnetic particles (top) and signal detection (bottom). (b) Schematic diagram of the device. (c) Photograph of an actual microcoil which generates radio frequency (RF) magnetic fields to excite samples and receives the resulting NMR signal. (d) Image of a microfluidic network. (e) Schematic of the NMR electronics. Reprinted from Ref [93] by permission of Nature Publishing Group.