Label‐Free Virus Capture and Release by a Microfluidic Device Integrated with Porous Silicon Nanowire Forest

Abstract

Viral diseases are perpetual threats to human and animal health. Detection and characterization of viral pathogens require accurate, sensitive and rapid diagnostic assays. For field and clinical samples, the sample preparation procedures limit the ultimate performance and utility of the overall virus diagnostic protocols. Here, we presented the development of a microfluidic device embedded with porous silicon nanowire (pSiNW) forest for label-free size-based point-of-care virus capture in a continuous curved flow design. The pSiNW forests with specific inter-wire spacing were synthesized in situ on both bottom and sidewalls of the microchannels in a batch process. With the enhancement effect of Dean flow, we demonstrated ~50% H5N2 avian influenza viruses were physically trapped without device clogging. A unique feature of the device is that captured viruses can be released by inducing self-degradation of the pSiNWs in physiological aqueous environment. About 60% of captured viruses can be released within 24 hours for virus culture, subsequent molecular diagnosis and other virus characterization and analyses. This device performs viable, unbiased and label-free virus isolation and release. It has great potentials for virus discovery, virus isolation and culture, functional studies of virus pathogenicity, transmission, drug screening, and vaccine development.

Inertial Microfluidics Enabling Clinical Research

“…Diagnosis and treatment of viral infections require isolation of sub-micrometer viral particles and proteins from bodily fluids containing a large background of endogenous human cells. Direct manipulation of viral particles (20–400 nm) is challenging in inertial microfluidic (IM) because it is difficult to achieve sufficient shear gradient forces to influence nanoscale viruses [ 185 , 186 ]. Consequently, IM technologies focus on the indirect isolation of viruses [ 185 , 186 ] and clinically relevant antibodies [ 187 ] from blood samples by inertially focusing large blood cells for removal.…”

Microfluidic devices for detection of RNA viruses

“…Xia et al developed a microfluidic device embedded with porous silicon nanowire (pSiNW) forest for label‐free size‐based point‐of‐care virus capture in a continuous curved flow design. They worked on Influenza virus (H5N1) and demonstrated that this method could have high potentials for virus discovery, isolation, and culture 84 …”

Label-free microfluidic sorting of microparticles

“…Cross-flow microfiltration has a wide range of applications, such as separation on nano- 162 and microscales, 163 enrichment, 244 and isolation of extracellular vesicles 164 and CTCs 161 from complex biosamples. Yoon et al 161 utilized weir filters to continuously separate CTCs from whole blood, achieving a separation efficiency of 97% [Fig.…”