Researchers create unique graphene nanopores with optical antennas for DNA sequencing

High-speed reading of the genetic code should get a boost with the creation of the world's first graphene nanopores – pores measuring approximately 2 nanometers in diameter – that feature a "built-in" optical antenna.

Researchers with Berkeley Lab and the University of California (UC) Berkeley have invented a simple, one-step process for producing these nanopores in a graphene membrane using the photothermal properties of gold nanorods.

"With our integrated graphene nanopore with plasmonic optical antenna, we can obtain direct optical DNA sequence detection," says Luke Lee, the Arnold and Barbara Silverman Distinguished Professor at UC Berkeley.

Lee and Alex Zettl, a physicist who holds joint appointments with Berkeley Lab's Materials Sciences Division and UC Berkeley's Physics Department, were the leaders of a study in which a hot spot on a graphene membrane formed a nanopore with a self-integrated optical antenna. The hot spot was created by photon-to-heat conversion of a gold nanorod."We believe our approach opens new avenues for simultaneous electrical and optical nanopore DNA sequencing and for regulating DNA translocation," says Zettl, who is also a member of the Kavli Energy Nanoscience Institute (Kavli ENSI).

Nanopore sequencing of DNA, in which DNA strands are threaded through nanoscale pores and read one letter at a time, has been touted for its ability to make DNA sequencing a faster and more routine procedure. Under today's technology, the DNA letters are "read" by an electrical current passing through nanopores fabricated on a silicon chip. Trying to read electrical signals from DNA passing through thousands of nanopores at once, however, can result in major bottlenecks. Adding an optical component to this readout would help eliminate such bottlenecks.