Highly Sensitive Black Phosphorous and Si-Based SPR Sensor for Formalin Detection Applications

The concern regarding formalin contamination and mixing poses a significant health threat, particularly in tropical areas, thereby necessitating the development of highly sensitive detection techniques. In this research, a sensor utilizing surface plasmon resonance (SPR) is developed and examined theoretically to attain optimal sensitivity and remarkable selectivity in the detection of formalin. The optimized design integrates BK7, TiO<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf>, silver (Ag), silicon (Si) and additional layers of BP, reaching an exceptional sensitivity of 298.3°/RIU, a detection accuracy of 0.427899016/°, and a figure of merit (FOM) of 127.6423 (1/RIU), which is crucial to improve sensor performance by facilitating improved charge carrier confinement and efficient charge transfer at the metal interface. In addition, the distribution of the electric field is studied to assess the field enhancement at material interfaces.