Differentiation of Complex Vapor Mixtures Using Versatile DNA–Carbon Nanotube Chemical Sensor Arrays

Abstract

Vapor sensors based on functionalized carbon nanotubes (NTs) have shown great promise, with high sensitivity conferred by the reduced dimensionality and exceptional electronic properties of the NT. Critical challenges in the development of NT-based sensor arrays for chemical detection include the demonstration of reproducible fabrication methods and functionalization schemes that provide high chemical diversity to the resulting sensors. Here, we outline a scalable approach to fabricating arrays of vapor sensors consisting of NT field effect transistors functionalized with single-stranded DNA (DNA-NT). DNA-NT sensors were highly reproducible, with responses that could be described through equilibrium thermodynamics. Target analytes were detected even in large backgrounds of volatile interferents. DNA-NT sensors were able to discriminate between highly similar molecules, including structural isomers and enantiomers. The sensors were also able to detect subtle variations in complex vapors, including mixtures of structural isomers and mixtures of many volatile organic compounds characteristic of humans.

Two star‐shaped tetranuclear Ru(II) complexes containing uncoordinated imidazole groups: synthesis, characterization, photophysical and pH sensing properties

“…Materials 2,2′-Bipyridine, 1,10-phenanthroline, 4-hydroxybenzaldehyde, 3hydroxybenzaldehyde, 1,2,4,5-tetrakis(bromomethyl)benzene, ethylene glycol, sodium, tetrabutylammonium perchlorate (TBAP), RuCl 3 ·3H 2 O, NH 4 PF 6 , K 2 CO 3 , NH 4 OAc, ethyl ether, AcOH, CH 3 CN, CH 2 Cl 2 , EtOH, MeOH, and N,N-dimethylformamide (DMF) were purchased from the Tianjin Chemical Reagent Factory. Solvents and raw materials were of analytical grade and used as received, apart from CH 3 CN, which was filtered over activated alumina and distilled from P 2 O 5 immediately prior to use.…”

“…Molecules responding to external stimulation have received much attention in recent years, and are potentially useful in the design of molecular switches and molecular machines (1)(2)(3)(4)(5). Transfer of protons can be regarded as one of the simplest but very important chemical signals.…”

Carbon Nanotube Based Gas Sensors toward Breath Analysis

“…Kybert et al. studied the use of DNA‐functionalized SWCNTs as the sensing element in FET devices for VOC differentiation . DNA is an attractive functionalizing agent because its complex chemistry and controllable synthesis allows limitless array combinations and reproducibility.…”

“…Kybert et al studied the use of DNA-functionalized SWCNTsa st he sensinge lement in FET devices for VOC differentiation. [99] DNA is an attractive functionalizing agent because its complex chemistry and controllable synthesis allows limitless array combinationsa nd reproducibility.I nt his study,f our single-stranded DNA oligomers (Table 3) were used to nonco-valentlyf unctionalize SWCNT FET devices, which were then independently tested against isomers of organic odorous compoundsl imolene and pinene ( Figure 12 d). The Seq1/SWCNT device had al arge differencei nr esponse towardl imolene enantiomers (Figure 12 a), whereas the responses of Seq1 and Seq3 devicest ot he isomerso fp inenea nd mixtures of the isomers showed ah igha mount of variance ( Figure 12 ba nd c).…”

“…DNA oligomersu sed to functionalizes-SWCNTs . [99] NameD NA sequence markersf or lung cancer.A na rray of random network CNT (RN-CNTs) chemiresistors were coated with av ariety of thin organic films and exposed to simulated "healthy" and "cancerous" breath. The two simulated breath patternsc ould not be distinguished at highl evels of humidity;h owever,w hen ap reconcentrations tep was used to separate VOCs from humidity,t he healthya nd cancerous breath patterns could be easily distinguished with PCA ( Figure 13).…”