First-Principles Density Functional Theory Calculations on the Potential of Sc₂CO₂ MXene Nanosheets as a Dual-Mode Sensor for Detection of Volatile Organic Compounds in Exhaled Human Breath

Abstract

Volatile organic compounds (VOCs), namely, acetone, ethanol, acetonitrile, 2-propanol, isoprene, and toluene exhaled in human breath act as potential biomarkers for the identification of certain physiological disorders. This work investigates the sensing capability of two-dimensional Sc2CO2 MXene nanosheets toward these VOCs using first-principles density functional theory calculations. Since carbon dioxide and water vapor persist in the exhaled breath, their interaction with Sc2CO2 as interferent species is examined too. It is found that 2-propanol (−0.63 eV), ethanol (−0.59 eV), and acetonitrile (−0.51 eV) show higher interaction with the Sc2CO2. Meanwhile, the chemiresistive sensorial behavior has been examined, and it is revealed that Sc2CO2 is highly sensitive to acetonitrile (50.20%). Both ethanol (1.03 × 10–3 s) and 2-propanol (5.24 × 10–3 s) have a fast recovery at room temperature. Alternatively, the change in work function of Sc2CO2 nanosheets on adsorption of VOC biomarkers has been examined. The corresponding results have proved that the work function-based Sc2CO2 sensor is sensitive to physisorbed species like toluene (47.62%) and isoprene (37.83%) that are not quantifiable using the chemiresistive sensing mechanism. Overall, our research predicts that the Sc2CO2 MXene nanosheet can be utilized as a dual-mode sensor to detect potential VOC biomarkers in the exhaled breath. Also, our results will assist the experimentalists in designing MXene nanosheet-based room-temperature sensors as point-of-care breathalyzers for disease diagnosis.

Identification of Lung Cancer Biomarkers by Nanosensors Based on Titanium Carbide (Ti3C2Tx) MXenes

“…We further compare the calculated E ads of the selected VOCs with MXenes to those of other sensing materials in the literature. The E ads values of aniline on BeO nanotubes (−0.40 eV), ethyl benzene on Zn(100) (−0.30 eV), isoprene on Sc 2 CO 2 (−0.17 eV), and o-toluidine on square-octagon arsenene nanotubes (−0.33 eV) were weaker than the reported E ads values on MXenes (Ti 3 C 2 T x ; T x = O, S, F, and OH) systems.…”

“…Despite their fascinating sensing properties, applications of MXenes in VOCs sensing have been less explored. Acetone, ethanol, acetonitrile, 2-propanol, isoprene, and toluene in human breath were detected with Sc 2 CO 2 MXenes using DFT calculations . Alcohols and toluene were used as breast and lung cancer biomarkers, respectively.…”

Novel Structural and Electronic Properties, Magnetic Anisotropy and Quantum Capacitance of Cr2/3Sc1/3CO2 I‐Mxene

“…The WF of Cr 2 CO 2 is ≈7.7 eV according to You et al, [59] while the WF of Sc 2 CO 2 is 4.679 eV. [60] The WF of the F4-TCNQ film is ≈5.55 eV, which provides good hole injection electrodes. [61] The WFs of Ti 2(1-x) V 2x CO 2 i-MXene with x = 0.25, 0.5, and 0.75 range from 5.84 to 6.32 eV.…”

Unveiling the potential of Ti3C2Tx MXene for gas sensing: recent developments and future perspectives

“…Reji et al demonstrated the Sc 2 CO 2 MXene nanosheets for detection of VOCs using first-principles DFT calculations. 132 They reported that 2-propanol (−0.63 eV), ethanol (−0.59 eV), and acetonitrile (−0.51 eV) show higher interaction with the Sc 2 CO 2 MXene nanosheets. At the end, they also predict that Sc 2 CO 2 MXene nanosheets can be utilized as a dual-mode sensor to detect potential VOC biomarkers in the exhaled breath.…”