{"id":1826,"date":"2017-10-25T15:58:02","date_gmt":"2017-10-25T15:58:02","guid":{"rendered":"http:\/\/chemweb.unl.edu\/sinitskii\/?p=1826"},"modified":"2025-04-14T17:18:16","modified_gmt":"2025-04-14T17:18:16","slug":"gnr-sensors-unl-news","status":"publish","type":"post","link":"http:\/\/chemweb.unl.edu\/sinitskii\/gnr-sensors-unl-news\/","title":{"rendered":"[UNL News] New graphene nano-ribbons lend sensors unprecedented sensitivity"},"content":{"rendered":"
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[New graphene nano-ribbons lend sensors unprecedented sensitivity<\/em> | University Communications | 10\/20\/2017]
\nPinning DNA-sized ribbons of carbon to a gas sensor can boost its sensitivity far better than any other known carbon material, says a new study from the University of Nebraska-Lincoln.<\/p>\n

The team developed a new form of nano-ribbon made from graphene, a 2-D honeycomb of carbon atoms. When the researchers integrated a film of the nano-ribbons into the circuitry of a gas sensor, it responded about 100 times more sensitively to molecules than did sensors featuring even the best-performing carbon-based materials.<\/p>\n

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Alexey Lipatov; Nature Communications \/ Springer Nature<\/em><\/p>\n<\/div>\n

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\u201cWe previously studied sensors based on other carbon-based materials such as graphene and graphene oxide,\u201d said Alexander Sinitskii, associate professor of chemistry at Nebraska. \u201cIn the case of graphene nano-ribbons, we were certain that we would see some sensor response, but we did not expect that it would be that much higher than anything we have seen in the past.\u201d<\/p>\n

Reporting their findings in the journal\u00a0Nature Communications<\/a>, the researchers showed that gas molecules can dramatically alter the electrical resistance of nano-ribbon films. Different gases produced varying resistance signatures, allowing the sensor to distinguish among them.<\/p>\n

\u201cWith multiple sensors on a chip, we were able to demonstrate that we can differentiate between molecules that have nearly the same chemical nature,\u201d said Sinitskii, a member of the\u00a0Nebraska Center for Materials and Nanoscience<\/a>. \u201cFor example, we can tell methanol and ethanol apart. So these sensors based on graphene nano-ribbons can be not only sensitive but also selective.\u201d<\/p>\n

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This rendering shows gas molecules widening the gaps between rows of the team’s graphene nano-ribbons. Nebraska’s Alexander Sinitskii and his colleagues have proposed that this phenomenon partly explains how the nano-ribbons grant sensors an unprecedented boost in sensitivity.<\/em><\/span><\/div>\n<\/div>\n<\/div>\n<\/div>\n

 
\nSinitskii and his colleagues suspect that the nano-ribbons\u2019 remarkable performance stems partly from an unusual interaction between the ribbons and gas molecules. Unlike its predecessors, the team\u2019s nano-ribbons \u2014 which resemble ordered rows of Charlie Brown\u2019s shirt stripes \u2014 stand vertically rather than lying flat on a surface. The team has proposed that gas molecules can nudge these rows apart, effectively lengthening the gaps between nano-ribbons that electrons must jump to conduct electricity.<\/p>\n

Enter the (benzene) ring<\/strong><\/p>\n

Graphene, whose 2004 discovery eventually earned a Nobel Prize, boasts unmatched electrical conductivity. But the material\u2019s lack of a band gap \u2014 which requires electrons to gain energy before jumping from their near orbits around atoms to an outer \u201cconduction band\u201d that drives conductivity \u2014 initially prevented researchers from switching off that conductivity. This, in turn, posed challenges to applying graphene in electronics that require adjusting the material\u2019s conductivity at will.<\/p>\n

One potential solution involved trimming sheets of graphene down to nanoscopic ribbons that computer simulations suggested would possess the elusive band gap. This proved difficult to do with the atomic precision needed to preserve the properties that made graphene appealing in the first place, so researchers began fabricating ribbons from the bottom up by strategically snapping together molecules on certain types of solid surfaces. Though the process worked \u2013 and the resulting ribbons did have a band gap \u2013 it limited researchers to fabricating just a few ribbons at a time.<\/p>\n

In 2014, Sinitskii pioneered an approach that could\u00a0mass-produce nano-ribbons in a liquid solution<\/a>, a vital step toward scaling up the technology for electronic applications. But the films made from these nano-ribbons were not conductive enough to perform electrical measurements. The team\u2019s newest study adapted the original chemical approach by adding benzene rings \u2014 circular molecules with six atoms of both carbon and hydrogen \u2014 onto either side of a first-generation nano-ribbon. These rings widened the ribbon, reducing its band gap and enhancing its ability to conduct electricity.<\/p>\n

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A sensing chip that can accommodate nanoscopically thin films of the team’s graphene nano-ribbons.<\/em><\/div>\n<\/div>\n<\/div>\n<\/div>\n

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\u201cPeople do not often think of graphene nano-ribbons as a sensor material,\u201d Sinitskii said. \u201cHowever, the same (property) that makes the nano-ribbons good for devices such as transistors \u2013 the ability to change their conductivity by several orders of magnitude \u2014 is also what makes them good for sensors.<\/p>\n

\u201cIt is possible to design many different kinds of graphene nano-ribbons with very diverse properties. Only a few types have been experimentally demonstrated so far, but there are many interesting theoretical predications about ribbons that are yet to be synthesized by chemists. So it is very likely that new nano-ribbons with even better sensor characteristics or other exciting properties will be developed in the near future.\u201d<\/p>\n

Sinitskii authored the study with Nebraska\u2019s Alexey Lipatov, research assistant professor of chemistry; Mohammad Mehdi Pour and Mikhail Shekhirev, doctoral students in chemistry; Rafal Korlacki, research engineer in electrical and computer engineering; the University of Illinois at Urbana-Champaign\u2019s Adrian Radocea, Ximeng Liu, Tao Sun, Narayana Aluru and Joseph Lyding; and Victor Sysoev and Andrey Lashkov of Saratov State Technical University.<\/p>\n

The researchers received support primarily from the\u00a0National Science Foundation<\/a>, the Office of Naval Research and the Nebraska Research Initiative.<\/p>\n","protected":false},"excerpt":{"rendered":"","protected":false},"author":1,"featured_media":2391,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"aside","meta":{"jetpack_post_was_ever_published":false,"jetpack_publicize_message":"","jetpack_is_tweetstorm":false,"jetpack_publicize_feature_enabled":true,"jetpack_social_post_already_shared":true,"jetpack_social_options":{"image_generator_settings":{"template":"highway","enabled":false}}},"categories":[4],"tags":[],"jetpack_publicize_connections":[],"jetpack_featured_media_url":"http:\/\/chemweb.unl.edu\/sinitskii\/wp-content\/uploads\/2025\/04\/Nanoribbons.png","jetpack_sharing_enabled":true,"jetpack_shortlink":"https:\/\/wp.me\/p5qrjz-ts","_links":{"self":[{"href":"http:\/\/chemweb.unl.edu\/sinitskii\/wp-json\/wp\/v2\/posts\/1826"}],"collection":[{"href":"http:\/\/chemweb.unl.edu\/sinitskii\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/chemweb.unl.edu\/sinitskii\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/chemweb.unl.edu\/sinitskii\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/chemweb.unl.edu\/sinitskii\/wp-json\/wp\/v2\/comments?post=1826"}],"version-history":[{"count":8,"href":"http:\/\/chemweb.unl.edu\/sinitskii\/wp-json\/wp\/v2\/posts\/1826\/revisions"}],"predecessor-version":[{"id":2393,"href":"http:\/\/chemweb.unl.edu\/sinitskii\/wp-json\/wp\/v2\/posts\/1826\/revisions\/2393"}],"wp:featuredmedia":[{"embeddable":true,"href":"http:\/\/chemweb.unl.edu\/sinitskii\/wp-json\/wp\/v2\/media\/2391"}],"wp:attachment":[{"href":"http:\/\/chemweb.unl.edu\/sinitskii\/wp-json\/wp\/v2\/media?parent=1826"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/chemweb.unl.edu\/sinitskii\/wp-json\/wp\/v2\/categories?post=1826"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/chemweb.unl.edu\/sinitskii\/wp-json\/wp\/v2\/tags?post=1826"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}