The development of sensitive graphene-based surface acoustic wave sensors for NO2 detection at room temperature

• Published in: Mikrochimica acta (1966) 2024-06, Vol.191 (6), p.323, Article 323
• Main Authors: Buiculescu, Valentin, Dinu, Livia Alexandra, Veca, Lucia Monica, Pârvulescu, Cătălin, Mihai, Madalina, Brîncoveanu, Oana, Comănescu, Florin, Brașoveanu, Costin, Stoian, Marius, Baracu, Angela Mihaela
• Format: Article
• Language: English
• Subjects: Analytical Chemistry; Bilayers; Characterization and Evaluation of Materials; Chemistry; Chemistry and Materials Science; Graphene; Microengineering; Nanochemistry; Nanotechnology; Nitrogen dioxide; Original Paper; Room temperature; Sensitivity; Sensors; Surface acoustic wave devices
• ISSN: 0026-3672; 1436-5073; 1436-5073
• DOI: 10.1007/s00604-024-06397-y

Bilayer graphene (Bl-Gr) and sulphur-doped graphene (S-Gr) have been integrated with LiTaO 3  surface acustic wave (SAW) sensors to enhance the performance of NO 2 detection at room temperature. The sensitivity of the Bl-Gr SAW sensors toward NO 2 , measured at room temperature, was 0.29º/ppm, with a limit of detection of 0.068 ppm. The S-Gr SAW sensors showed 0.19º/ppm sensitivity and a limit of detection of 0.140 ppm. The origin of these high sensitivities was attributed to the mass loading and elastic effects of the graphene-based sensing materials, with surface changes caused by the absorption of the NO 2 molecules on the sensing films. Although there are no significant differences regarding the sensitivity and detection limit of the two types of sensors, the measurements in the presence of interferent gases and various humidity conditions outlined much better selectivity and sensing performances towards NO 2 gas for the Bl-Gr SAW sensors. Graphical Abstract