Berkeley 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.
Schematic drawing of graphene nanopore with self-integrated optical antenna (gold) that enhances the optical readout signal (red) of DNA as it passes through a graphene nanopore.
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.
“Direct and enhanced optical signals are obtained at the junction of a nanopore and its optical antenna,” says Lee. “Simultaneously correlating this optical signal with the electrical signal from conventional nanopore sequencing provides an added dimension that would be an enormous advantage for high-throughput DNA readout.”
A key to the success of this effort is the single-step photothermal mechanism that enables the creation of graphene nanopores with self-aligned plasmonic optical antennas. The dimensions of the nanopores and the optical characteristics of the plasmonic antenna are tunable, with the antenna functioning as both optical signal transducer and enhancer.
The atomically thin nature of the graphene membrane makes it ideal for high resolution, high throughput, single-molecule DNA sequencing. DNA molecules can be labeled with fluorescent dyes so that each base-pair fluoresces at a signature intensity as it passes through the junction of the nanopore and its optical antenna.
“In addition, either the gold nanoplasmonic optical antenna or the graphene can be functionalized to be responsive to different base-pair combinations,” Lee says. “The gold plasmonic optical antenna can also be functionalized to enable the direct optical detection of RNA, proteins, protein-protein interactions, DNA-protein interactions, and other biological systems.”
The results of this study were reported in Nano Letters in a paper titled “Graphene Nanopore with a Self-Integrated Optical Antenna.” Lee is the corresponding author. Other co-authors in addition to Zettl were SungWoo Nam, Inhee Choi, Chi-cheng Fu, Kwanpyo Kim, SoonGweon Hong and Yeonho Choi.
This research was primarily supported by the DOE Office of Science.
Lynn Yarris | EurekAlert!
Astronomers find unexpected, dust-obscured star formation in distant galaxy
24.03.2017 | University of Massachusetts at Amherst
Gravitational wave kicks monster black hole out of galactic core
24.03.2017 | NASA/Goddard Space Flight Center
Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.
The results will be published on March 22 in the journal „Astronomy & Astrophysics“.
Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...
Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.
Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...
In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...
Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to simulate these confined natural conditions in artificial vesicles for the first time. As reported in the academic journal Small, the results are offering better insight into the development of nanoreactors and artificial organelles.
Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to...
20.03.2017 | Event News
14.03.2017 | Event News
07.03.2017 | Event News
24.03.2017 | Materials Sciences
24.03.2017 | Physics and Astronomy
24.03.2017 | Physics and Astronomy