Nucleic acid hybridization on an electrically reconfigurable network of gold-coated magnetic nanoparticles enables microRNA detection in blood

Magnetic nanoparticles can catch cancers early

31 July 2019

Trace quantities of tumour biomarkers can be detected in unprocessed blood samples using nanoparticle technology developed at the University of New South Wales. The electrochemistry-based approach could become the basis of a low-cost device to catch cancers long before outward symptoms arise.

From their earliest phases of development, tumours release snippets of genetic material called microRNAs into the bloodstream. For example, solid tumours such as carcinomas release an aberrant miRNA called miR-21 — but at ultralow concentrations. The current method for trace miRNA detection needs purified blood samples, is labour intensive and time consuming.

The team developed a method to rapidly detect miR-21 in unprocessed blood. They produced gold-coated magnetic nanoparticles covered with DNA strands that selectively stick to miR-21. After mixing the particles with a blood sample, the team used a magnetic field to isolate the nanoparticles, then applied an electric current to the sample. Captured miR-21 affected the flow of electric current between particles, which could be easily measured to detect the target miRNA even at sub-nanomolar concentrations.

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References

1. Nature Nanotechnology 13, 1066–1071 (2018). doi: 10.1038/s41565-018-0232-x