Surface Plasmon Resonance–Based Biosensor Design Using Circular Disk and Thin Wire Resonator for Alcohol Detection

Abstract

In the production of alcohol, methanol is produced, and it is toxic to the human body. Methanol poisoning is the biggest cause of the increased death ratio, and it is necessary to control it with fast detection. This study presents a novel design for metal oxide–based alcohol sensors (MOBASs) that achieves exceptional selectivity for methanol detection. The sensor exhibits a remarkably high sensitivity of 2813 nm/RIU for methanol and ethanol within the 1250–1550 nm wavelength range, demonstrating a superior ability to distinguish between these alcohols. Methanol (MeOH) has 99.98% reflection, whereas ethanol (EtOH) gets 68.66%, which makes it more suitable for this sensing application. Other important parameters such as the figure of merit (FOM), quality factor (QF), and detection limit (DL) are 5484.45, 2875.63, and 0.30 × 10⁻⁴ RIU, respectively. By comparing six different structures (D-1 to D-6) of MOBAS, it is easy to identify a good response in terms of transmission.