More-sensitive DNA nanowires promise better measurements of biological processes

Scientists have developed a new, gold-tipped nanowire that is 100 times more sensitive than previous versions of the technology. The nanowires could be used to more precisely measure multiple biological processes at the same time.

All previous iterations of the unique sensor have been two-dimensional, but scientists at KTH Royal Institute of Technology and Stockholm University developed a way to build DNA nanowires in 3D.

"Our geometry makes it much easier to measure several biomolecules simultaneously, and is also 100 times more sensitive," Wouter van der Wijngaart, a professor at KTH, said in a news release. "This is the first out-of-plane metallic nanowire formation based on stretching of DNA through a porous membrane."

DNA nanowires are designed to identify specific biomarker molecules in the test subject, even at extremely low concentrations. The technology could be used to detect and treat cancer, infections and other health problems.

Construction of the nanoscale DNA wires begins with the capture of specific molecules in a porous membrane. The molecules are designed to bind with specific biomarkers. The binding process stretches DNA molecules through pores in the membrane, forming the nanoscale ware.

"The DNA strands are stretched through the pores in the membrane during liquid removal by forced convection," scientists wrote in their paper, published in the journal Nature Microsystems & Nanoengineering. "Because the liquid-air interface movement across the membrane occurs in every pore, DNA stretching across the membrane is highly efficient."

The DNA nanowire is then treated with gold nanoparticles, making it conductive. The wire is organized to only bind with certain DNA sequences inside the test subject.

Nanowires like the kind developed by researchers at KTH and Stockholm University can be used to detect the presence of diseases and genetic disorders.