A graphene/gold-coated surface plasmon sensor for sodium nitrate detection

• Main Authors: Zain, Huda Adnan, Batumalay, Malathy, Harith, Z., Rahim, Hazli Rafis Abdul, Harun, Sulaiman Wadi
• Format: Article
• Published: MDPI 2022
• Subjects: QC Physics
• Online Access: http://eprints.um.edu.my/41409/

A sodium nitrate sensor with graphene/gold coating is presented in this paper. A Kretschmann setup with angle interrogation was used to detect sodium nitrate in the range of 0-15%. Using a graphene coating on top of the 50 nm gold layer showed an improvement in the sensitivity of the sensor. The gold-coated setups had a sensitivity of 0.198 degrees/%. In contrast, the graphene/gold-coated samples showed a sensitivity of 0.244 degrees/% due to the charge transfer between the graphene and the gold and the resulting excited solid electric field. The graphene/gold-coated sensor showed good stability with time in the temperature range of 19-34 degrees C. This shows that this setup may be beneficial in detecting sodium nitrate.