Extracellular vesicles (EV) containing microRNAs (miRNAs) have tremendous potential as biomarkers for the early detection of disease. Here, we present a simple and rapid PCR-free integrated microfluidics platform capable of absolute quantification (<10% uncertainty) of both free-floating miRNAs and EV-miRNAs in plasma with 1 pM detection sensitivity. The assay time is only 30 minutes as opposed to 13 h and requires only ~20 μL of sample as oppose to 1 mL for conventional RT-qPCR techniques. The platform integrates a surface acoustic wave (SAW) EV lysing microfluidic chip with a concentration and sensing microfluidic chip incorporating an electrokinetic membrane sensor that is based on non-equilibrium ionic currents. Unlike conventional RT-qPCR methods, this technology does not require EV extraction, RNA purification, reverse transcription, or amplification. This platform can be easily extended for other RNA and DNA targets of interest, thus providing a viable screening tool for early disease diagnosis, prognosis, and monitoring of therapeutic response.

We report a new Bifurcated Continuous Field-Flow Fractionation (BCFFF) microfluidic chip for isolation and purification of nucleic acids from blood plasma with high and concentration-independent yield. The platform is ideal for isolation and quantification of small miRNAs.

Superparamagnetic nanobeads offer several advantages over microbeads for immunocapture of nanocarriers (extracellular vesicles, lipoproteins, and viruses) in a bioassay: high-yield capture, reduction in incubation time, and higher capture capacity. However, nanobeads are difficult to “pull-down” because their superparamagnetic feature requires high nanoscale magnetic field gradients. Here, an electrodeposited track-etched membrane is shown to produce a unique superparamagnetic nano-edge ring with multiple edges around nanopores. With a uniform external magnetic field, the induced monopole and dipole of this nano edge junction combine to produce a 10× higher nanobead trapping force. A dense nanobead suspension can be filtered through the magnetic nanoporous membrane (MNM) at high throughput with a 99% bead capture rate. The yield of specific nanocarriers in heterogeneous media by nanobeads/MNM exceeds 80%. Reproducibility, low loss, and concentration-independent capture rates are also demonstrated. This MNM material hence expands the application of nanobead immunocapture to physiological samples.

Superparamagnetic nanobeads offer several advantages over microbeads for immunocapture of specifc molecular nanocarriers (extracellular vesicles, lipoproteins, and viruses) in a bioassay: high-yield capture, reduction in incuba-tion time and higher capture capacity. However, nanobeads are difficult to “pull down” because their superparamag-netic feature requires high nanoscale magnetic field gradients in addition to high magnetic fields. Here, electroplated track-etched membrane is shown to produce a unique superparamagnetic nanowedge ring with multiple edges around each nanopore. With a uniform external magnetic field, the induced monopole and dipole of this nanowedge junction combine to produce a 10x higher nanobead trapping force. A dense nanobead suspension can be filtered through the magnetic nanoporous membrane (MNM) at a high-throughput with 99% bead capture rate. The capture yield of specific nanocarriers in heterogeneous media (filtered plasma and conditioned cell media) by nanobeads/MNM ex-ceeds 80%. Quantification of RNA cargo in captured extracellular vesicles demonstrate 60x increase in capture rate of a specific microRNA relative to magnetic bead columns. Reproducibility, low loss, and concentration-independent capture rates are also demonstrated. This new MNM material hence significantly expands the application of nano-bead immunocapture to heterogeneous physiological samples, such as blood and saliva, whose molecular analytes are cargoes of nanocarriers.

Superparamagnetic nanobeads offer several advantages over microbeads for immunocapture of specific molecular nanocarriers (extracellular vesicles, lipoproteins, and viruses) in a bioassay: high-yield capture, reduction in incubation time, and higher capture capacity. However, nanobeads are difficult to “pull-down” because their superparamagnetic feature requires high nanoscale magnetic field gradients in addition to high magnetic fields. Here, an electroplated track-etched membrane is shown to produce a unique superparamagnetic nano edge ring with multiple edges around each nanopore. With a uniform external magnetic field, the induced monopole and dipole of this nano edge junction combine to produce a 10x higher nanobead trapping force. A dense nanobead suspension can be filtered through the magnetic nanoporous membrane (MNM) at high throughput with a 99% bead capture rate. The capture yield of specific nanocarriers in heterogeneous media (filtered plasma and conditioned cell media) by nano-beads/MNM exceeds 80%. Quantification of RNA cargo in captured extracellular vesicles demonstrates a 60x increase in the capture rate of a specific microRNA relative to magnetic bead columns. Reproducibility, low loss, and concentration-independent capture rates are also demonstrated. This new MNM material hence significantly expands the application of nanobead immunocapture to heterogeneous physiological samples, such as plasma and saliva.