Detection of individual gas molecules adsorbed on graphene

Abstract

The ultimate aim of any detection method is to achieve such a level of sensitivity that individual quanta of a measured entity can be resolved. In the case of chemical sensors, the quantum is one atom or molecule. Such resolution has so far been beyond the reach of any detection technique, including solid-state gas sensors hailed for their exceptional sensitivity. The fundamental reason limiting the resolution of such sensors is fluctuations due to thermal motion of charges and defects, which lead to intrinsic noise exceeding the sought-after signal from individual molecules, usually by many orders of magnitude. Here, we show that micrometre-size sensors made from graphene are capable of detecting individual events when a gas molecule attaches to or detaches from graphene's surface. The adsorbed molecules change the local carrier concentration in graphene one by one electron, which leads to step-like changes in resistance. The achieved sensitivity is due to the fact that graphene is an exceptionally low-noise material electronically, which makes it a promising candidate not only for chemical detectors but also for other applications where local probes sensitive to external charge, magnetic field or mechanical strain are required.

Emerging Trends in Phosphorene Fabrication towards Next Generation Devices

“…The monolayer of BP, known as phosphorene, exhibits physical properties that can be significantly different from those of its bulk counterpart 16. Phosphorene has changed the landscape of many research areas in science and technology, particularly in condensed matter physics, and it has received much attention recently for its use as the base component of novel nanodevices, e.g., transistors, nanomechanical resonators, photovoltaics, photodetectors, batteries and sensors 9, 10, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37…”

Experimental Sensing and Density Functional Theory Study of H2S and SOF2 Adsorption on Au‐Modified Graphene

“…Graphene sheets have been increasingly used as transducers since the first successful attempt to apply graphene for chemical sensing and detection of single‐gas molecular absorption and desorption on graphene platforms 12. Experimental and theoretical studies have been conducted to elucidate the related gas adsorption mechanism.…”

Human‐Like Sensing and Reflexes of Graphene‐Based Films

“…Similar as the binding between odor and olfaction receptor neuron ( Figure 11 ),105 gas molecules would adsorb on the graphene sheets and induce conductance changes of graphene, which can be detected by measuring the changes of the electrical signal of graphene. Here, there are three modes of the interaction between gas molecules with graphene: a) influencing the conductance of graphene by redistributing electrons, such as H 2 O;106 b) contributing electrons or holes to graphene to change its electron concentration, such as NO 2 ;107 c) forming covalent bonds 108. Because of the adsorption of water molecules in air, the graphene often exhibits p‐type.…”

“…The mechanical exfoliated graphene was firstly used to fabricate graphene‐based gas sensor,106 which showed good sensitivity in detecting NO 2 , H 2 O, CO and NH 3 . What's more, the graphene‐based gas sensor also allowed the maximum sensitivity for detecting individual gas molecules.…”