Selective Gas Sensing with a Single Pristine Graphene Transistor

Abstract

We show that vapors of different chemicals produce distinguishably different effects on the low-frequency noise spectra of graphene. It was found in a systematic study that some gases change the electrical resistance of graphene devices without changing their low-frequency noise spectra while other gases modify the noise spectra by inducing Lorentzian components with distinctive features. The characteristic frequency f(c) of the Lorentzian noise bulges in graphene devices is different for different chemicals and varies from f(c) = 10-20 Hz to f(c) = 1300-1600 Hz for tetrahydrofuran and chloroform vapors, respectively. The obtained results indicate that the low-frequency noise in combination with other sensing parameters can allow one to achieve the selective gas sensing with a single pristine graphene transistor. Our method of gas sensing with graphene does not require graphene surface functionalization or fabrication of an array of the devices with each tuned to a certain chemical.

Graphene nanoelectronic heterodyne sensor for rapid and sensitive vapour detection

“…Using a 3s noise floor (3s ¼ 0.12 nA, Supplementary Fig. 1), the detection NATURE COMMUNICATIONS | DOI: 10.1038/ncomms5376 ARTICLE limit for DMMP is approximately 3 pg in mass or 0.64 ppb in concentration, which to our knowledge is the lowest for any uncoated, pristine nanoelectronic vapour sensor and similar to the best sensitivities reported on chemically coated nanoelectronic vapour sensors 17,19,20,28 . Our order of magnitude calculation also suggests that the noise floor corresponds to B10 4 molecules on the graphene surface (see Supplementary Notes 3 and 4).…”

“…However, a large device footprint (millimetre scale) is necessary for accurate capacitance measurement, and the use of chemoselective polymers in those devices significantly slows down the response time to hundreds of seconds. More recently, the low frequency noise spectrum of a graphene transistor was also used for chemical vapour sensing 20 by exploiting the third term in equation 1. Selective gas sensing was achieved on a single pristine graphene transistor, but the device suffered severely from extremely poor sensitivity and slow response time (4100 s).…”

“…As a result, device regeneration is achieved only through prolonged heating, current stimulation or ultraviolet radiation 8,[12][13][14]20,26,27 . Recently, various chemoselective surface coatings have been used 17,19,28 to reduce the response and recovery time to only a few seconds.…”

Changes in work function due to NO2 adsorption on monolayer and bilayer epitaxial graphene on SiC(0001)

“…Resistance measurements provide a highly sensitive means of determining the presence of molecular adsorbants on a graphene surface. Ensuring selectivity towards a particular molecule is more challenging, but can be achieved by functionalizing the surface with metallic dopants [1,2] or by analyzing the low-frequency noise after molecular adsorption [3]. Graphene-based NO 2 sensors have been shown to detect concentrations below 1 part per billion (ppb) [4,5].…”

Highly selective gas sensor arrays based on thermally reduced graphene oxide

“…Different gas molecules could be adsorbed on the surface of an rGO ake and change its conductivity, which would result in a poor selectivity of rGO-based sensors. Although a recent study suggests that some analytes could be recognized by their distinguishably different effects on the low-frequency noise spectra of graphene, 30 it remains unclear if a similar recognition could be performed using rGO sensors. Furthermore, such sensors are typically fabricated from rGO lms in which many akes of different size, shape, thickness, and degree of reduction partially overlap forming random junctions.…”