Graphene Oxide as a Sensing Material for Gas Detection Based on Nanomechanical Sensors in the Static Mode

Abstract

Graphene is a key material for gas sensing applications owing to its high specific surface area and vast chemical modification potential. To fully utilize the potential of graphene, a sensing platform independent of conductive properties is required. In this study, we employed membrane-type surface stress sensors (MSS)—A kind of nanomechanical sensor operated in the static mode—As a sensing platform and utilized graphene oxide (GO) as a gas sensing material. MSS detect surface stress caused by gas sorption; therefore, chemically modified graphene with low conductivity can be utilized as a gas sensing material. We evaluated the sensing performance of a GO-coated MSS by measuring its responses to five gases. We demonstrated with the GO-coated MSS the feasibility of GO as a gas sensing material for static mode nanomechanical sensors and revealed its high selectivity to water vapor. Moreover, we investigated the sensing mechanism of the GO-coated MSS by comparing it with the sensing performance of MSS coated with reduced graphene oxide and graphite powder and deduced key factors for sensitivity and selectivity. Considering the high sensitivity of the GO-coated MSS and the compact measurement system that MSS can realize, the present study provides a new perspective on the sensing applications of graphene.

Nanomechanical Gas Sensing with Laser Treated 2D Nanomaterials

“…For example, the increased number of oxygen functional groups and defects on the laser treated GO would increase the proportion of analyte molecules in the solid phase that are adsorbed onto the surface of the GO resulting in high K p and V a . [ 41 ] Furthermore, the unique properties of each analyte such as their molecule size, saturation vapor pressure, and intramolecular bonds are accounted for in K p and generate unique MSS signal response intensities. Through this model and sensing mechanism it is evident that laser treated 2D materials are suitable for use as receptor layers in MSS devices.…”

“…In a theoretical model presented by Wenzel et al. for coated microcantilevers (Equation (1)), the surface stress (σ) is proportionally dependent on the elastic modulus of the receptor material ( E R ), specific volume of the adsorbed gas ( V a ), partition coefficient of the gas ( K p ), and the concentration of the gas in the vapor phase ( C g ) [ 41,91,92 ] …”

“…2D materials typically have a high Young's modulus, [ 38,39 ] which has been shown to be advantageous for receptor materials incorporated into an MSS. [ 40,41 ] The MSS platform eliminates the need for highly conductive 2D materials, allowing the materials to be freely modified to improve their gas adsorption properties. Additionally, the mechanisms that contribute to increased sensor response of the 2D materials are experimentally investigated.…”

Development of a Mobile Device for Odor Identification and Optimization of Its Measurement Protocol Based on the Free-Hand Measurement

“…The basic sensing properties of the MSS chip was evaluated by a gas-sensing measurement system equipped with two mass flow controllers (MFCs) which provided dried nitrogen. The same measurement system was used in our previous studies [22][23][24]. One MFC (MFC1) was connected to a glass vial which contains a sample liquid; dried nitrogen from MFC1 delivered the vapor of the sample liquid.…”

Recent Developments in Graphene-Based Toxic Gas Sensors: A Theoretical Overview

“…As an alternative, among the carbon materials, graphene, a 2D monolayer form of sp 2 -hybridized carbon atoms, could prove a key material for sensing applications due to its exceptional thermal conductivity, high electron mobility, excellent mechanical properties, and high specific surface area [ 21 , 22 , 23 , 24 ]. Due to its remarkable properties, graphene opens up a wide range of promising applications in the sensors field, from fundamental science to industrial applications [ 25 , 26 , 27 , 28 , 29 ]. However, the main issue is that gas molecules are weakly adsorbed on graphene due to its low reactivity [ 30 , 31 , 32 ].…”