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Switched-on DNA to spark nano-electronic applications

February 20, 2017

ASU-led team develops 1st controllable DNA switch to regulate flow of electricity within single, atomic-size molecule

DNA, the stuff of life, may very well also pack quite the jolt for engineers trying to advance the development of tiny, low-cost electronic devices.

Much like flipping your light switch at home — only on a scale 1,000 times smaller than a human hair — an ASU-led team has now developed the first controllable DNA switch to regulate the flow of electricity within a single, atomic-size molecule. The new study, led by ASU Biodesign Institute researcher Nongjian Tao, was published in the advanced online journal Nature Communications

Nongjian (N.J.) Tao

“It has been established that charge transport is possible in DNA, but for a useful device, one wants to be able to turn the charge transport on and off. We achieved this goal by chemically modifying DNA,” said Tao, who directs the Biodesign Center for Bioelectronics and Biosensors and is a professor in the Fulton Schools of Engineering.

“Not only that, but we can also adapt the modified DNA as a probe to measure reactions at the single-molecule level. This provides a unique way for studying important reactions implicated in disease, or photosynthesis reactions for novel renewable energy applications.”

Engineers often think of electricity like water, and the research team’s new DNA switch acts to control the flow of electrons on and off, just like water coming out of a faucet.

Previously, Tao’s research group had made several discoveries to understand and manipulate DNA to more finely tune the flow of electricity through it. They found they could make DNA behave in different ways — and could cajole electrons to flow like waves according to quantum mechanics, or “hop” like rabbits in the way electricity in a copper wire works — creating an exciting new avenue for DNA-based, nano-electronic applications.

Tao assembled a multidisciplinary team for the project, including ASU postdoctoral student Limin Xiang and Li Yueqi performing bench experiments, Julio Palma working on the theoretical framework, with further help and oversight from collaborators Vladimiro Mujica (ASU) and Mark Ratner (Northwestern University).  

To accomplish their engineering feat, Tao’s group modified just one of DNA’s iconic double-helix chemical letters, abbreviated as A, C, T or G, with another chemical group, called anthraquinone (Aq). Anthraquinone is a three-ringed carbon structure that can be inserted in between DNA base pairs but contains what chemists call a redox group (short for reduction, or gaining electrons, or oxidation, losing electrons).

These chemical groups are also the foundation for how our bodies convert chemical energy through switches that send all of the electrical pulses in our brains and our hearts and communicate signals within every cell that may be implicated in the most prevalent diseases.

Tao’s group modified just one of DNA’s iconic double-helix chemical letters, abbreviated as A, C, T or G, with another chemical group, called anthraquinone (Aq). The modified Aq-DNA helix could now help it perform the switch, bestowing it with a newfound ability to reversibly gain or lose electrons.

 

The modified Aq-DNA helix could now help it perform the switch, slipping comfortably in between the rungs that make up the ladder of the DNA helix, and bestowing it with a newfound ability to reversibly gain or lose electrons.

Through their studies, where they sandwiched the DNA between a pair of electrodes, they careful controlled their electrical field and measured the ability of the modified DNA to conduct electricity. This was performed using a staple of nano-electronics, a scanning tunneling microscope, which acts like the tip of an electrode to complete a connection, being repeatedly pulled in and out of contact with the DNA molecules in the solution like a finger touching a water droplet.

“We found the electron transport mechanism in the present anthraquinone-DNA system favors electron ‘hopping’ via anthraquinone and stacked DNA bases,” said Tao. 

In addition, they found they could reversibly control the conductance states to make the DNA switch on (high-conductance) or switch off (low conductance). When anthraquinone has gained the most electrons (its most-reduced state), it is far more conductive, and the team finely mapped out a 3-D picture to account for how anthraquinone controlled the electrical state of the DNA.

For their next project, they hope to extend their studies to get one step closer toward making DNA nano-devices a reality.

“We are particularly excited that the engineered DNA provides a nice tool to examine redox reaction kinetics, and thermodynamics the single molecule level,” said Tao.

Find the complete list of study authors on the Biodesign Institute website.

 
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ASU production of 'The Magic Flute' offers a night at the opera

ASU’s Lyric Opera Theatre says 'The Magic Flute' is an ideal opera for novices.
February 22, 2017

ASU's Lyric Opera Theatre prepares students for careers in opera and music production

If you think opera is an acquired taste, think again. ASU’s Lyric Opera TheatreThe Lyric Opera Theatre program in the School of Music is housed in the Herberger Institute for Design and the Arts. says a new production of “The Magic Flute” is perfect for the novice palate.

“Most people hear the word ‘opera,’ and they get scared. The perception of opera is that it is sung by stuffy people with horns on their head that stand on stage and sing at people,” said Dale Dreyfoos, stage director and associate artistic director of Lyric Opera Theatre.

He added while that stereotype is still pervasive, “if you like musicals, you should like operas as well.”

Fighting that perception has been a lifelong battle for Dreyfoos, who began his performing career at the age of 10 in the Atlanta Boys Choir. A year later, he saw a performance of “The Magic Flute” and was “hooked on opera.”

Formed in 1964, Lyric Opera Theatre’s mission is to prepare opera and musical theatre artists for professional careers. Through individual and classroom instruction, the production of operas and musicals, student-led workshops and community engagement, ASU is working to help maintain the art form.

Hailed as one of Mozart’sWolfgang Amadeus Mozart died two months after it opened in September 1791. greatest musical masterpieces, the 200-year-old fairytale blends magic, mystery and humor with themes of love and good versus evil.

“It’s funny, fast-paced, full of surprises, plus the music is heavenly,” said Brian DeMaris, music director and artistic director of Lyric Opera Theatre. “The characters connect with the audience right away.”

The multi-media opera is double castThe opera is double cast to give students more opportunities and to fulfill their performance credits for their degree program., features more than 100 students and crew members, and runs nearly three hours.

“The Magic Flute” will be sung in German with English dialogue, and features “Der Holle Rache,” one of the most famous and ambitious arias in all of opera. Soprano Lauren Berman, who portrays the Queen of the Night, will perform the 2-minute vocal pyrotechnic on Friday and Sunday.

“It’s definitely a difficult aria,” said Berman, who is currently working on her doctorate in vocal performance. “I can tell if I haven’t had a good night’s sleep or have been over singing, because if I’m not at the top of my game, I can’t get through it. I’ve never had a role like this.”

The show also has its fair share of laughs, provided mostly by Papageno, a simple bird-catcher who yearns for a girlfriend and a glass of wine.

“Even though the story is close to 200 years old, the story, the issues and the characters are still the same as today,” said Nathan Haltiwanger, a first-year master’s student studying Opera Performance and one of two students who plays Papageno. “We feel we’ve made this opera more approachable in many ways.”

A lot of work goes into an opera production said Miriam Schildkret, a voice performance major who plays the Third Lady.

“If you’re not sweating at the end, you’re not doing it right,” Schildkret said.

“The Magic Flute” starts Thursday at Tempe’s Evelyn Smith Music Theatre and runs through Sunday. For more event information, including a link to buy tickets, click here.

 

Top photo: Sarastro's slave Monostatos, played by Ted Zimnicki, discloses his intention to force himself upon Pamina while she sleeps in ASU Lyric Opera Theatre's production of "The Magic Flute." Photo by Anya Magnuson/ASU Now.