Highly sensitive gold-film surface plasmon resonance (SPR) sensor employing germanium selenide (GeSe) nanosheets

Abstract Although surface plasmon resonance (SPR) methods are frequently employed due to their remarkable advantages such as reduced sample requirements, they confront a significant challenge in terms of sensitivity improvement. GeSe is an appropriate material for resolving this issue. According to the theoretical basis of the research, GeSe is a two-dimensional material which is a direct band gap semiconductor that may be utilized to promote electron transport and stimulate greater SPR phenomena. The first use of GeSe in an optical fiber sensor is reported in this study. A U-shaped optical fiber-GeSe-Au sensor is proposed. As a two-dimensional material with comparable physical characteristics to GeSe, MoS2 is compared to GeSe to characterize its influence upon the sensitivity. The sensitivity of fiber-GeSe-Au sensor is 7398.1 nm/refractive index unit (RIU), which is nearly twice as sensitive as a gold film SPR sensor and 1.5 times as sensitive as a sensor utilizing MoS2 nanosheets with the same structure. This study introduces a novel approach for enhancing the sensitivity, which gives a new option for monitoring biological substances at low concentrations with high sensitivity and stability and demonstrates that GeSe nanosheets have significant promise for future applications.