Graphene-Based Surface Plasmon Resonance Sensor for Water Salinity Concentration Detection Using Multiple Light Source Techniques

A Graphene-based surface plasmon resonance sensor is proposed for rapid water salinity concentration detection and operates with a new multiple light source technique. The proposed sensor consists of a CaF2 prism coupled with incident light of five different wavelengths. This multiple-source technique significantly increases the sensor detection accuracy and overall performance for the 1% to 30% water salinity concentration detection. The proposed sensor achieved a noticeably higher value sensitivity of 397.71 (deg./RIU), a Quality Factor of 99.50 (1/RIU), and a Figure of Merit of 94.82. The sensor also obtains a wide range of detection accuracy of 0.199 to 0.498 (1/deg.) while maintaining a considerably low minimum reflectance of 0.05 (normalized) for the whole salinity detection range. In addition, all of those performance parameters and results are compared to the most recent relevant works. The proposed salinity sensor obtained a significantly high sensitivity, a wide range of detection accuracy with higher efficiency, and overall improved performance. This impressive performances of the proposed Graphene-based SPR sensor for measuring water salinity level exhibited the highest sensitivity, wide range, high accuracy, efficiency, and reliability to detect water salinity concentration.