构建了一种新型表面等离子体共振杂化结构:单层石墨烯/少层Ti3C2TxMXene/银膜,采用传输矩阵法验证了二维材料Ti3C2TxMXene用于超灵敏表面等离子体共振传感的可行性。通过优化等离子体银膜厚度和Ti3C2TxMXene层数,该等离子体杂化结构的光子吸收和能量损耗达到有效平衡。理论计算结果表明,当入射光波为632.8 nm时,单层石墨烯/3层Ti3C2TxMXene/35 nm银膜的最优配置传感结构能够产生一个趋近于零的光学反射率(3.48×10 -9)。当传感界面发生0.0012 RIU的微弱折射率变化时,可实现110.55°的最大相位差响应,进而获得高达9.21×10 4(°)/RIU的相位探测灵敏度。相比于传统的基于角度调制的传感结构,该等离子体传感结构能够提高4个数量级的增强因子。 因此,所构建的新型表面等离子体共振杂化结构在超灵敏生化传感领域有良好的应用前景。

This study proposes a graphene monolayer/few layered Ti₃C₂T_x MXene/silver film as a new plasmonic hybrid nanostructure. The feasibility of two-dimensional Ti₃C₂T_x MXene in the ultrasensitive detection of surface plasmon resonance (SPR) was confirmed using the transfer matrix method. Calculation results show that both the photon absorption and energy loss are balanced by optimizing the thickness of Ti₃C₂T_x MXene and the silver film. In addition, under an excitation wavelength of 632.8 nm, the optimal sensing configuration is monolayer graphene/3-layered Ti₃C₂T_x MXene/35-nm silver film, which can produce an ultralow (approaching zero) SPR reflectivity (3.48×10 ^-9). For a minute variation in the refractive index (as small as 0.0012 RIU), the proposed configuration can produce a differential phase response up to 110.55°and provide a phase detection sensitivity as high as 9.21×10 ⁴ (°)/RIU. In comparison with the conventional sensing configuration with angular modulation, the proposed configuration can provide an enhancement factor that is four orders of magnitude higher. Therefore, our proposed configuration has potential application in ultrasensitive biochemical detection.