Fig. 1. Schematic of SPR sensor enhanced by two-dimensional Ti₃C₂Tx MXene nanosheet

Fig. 2. For the BAK1 prism/35 nm silver film/Ti₃C₂T_x MXene/monolayer graphene hybrid configuration, the calculated sensing performance by changing the number of Ti₃C₂T_x MXene layers when the excitation wavelength is 632.8 nm and the sensing medium is deionized water with the refractive index of 1.333. (a) Reflectivity; (b) phase

Fig. 3. SPR phase and reflectivity curves generated by the coupling BAK1 prism/35 nm silver film/3-layer Ti₃C₂T_x MXene/monolayer graphene when the excitation wavelength is 632.8 nm, and the sensing medium is deionized water with the refractive index of 1.333

Fig. 4. For the coupling BAK1 prism/silver film/Ti₃C₂T_x MXene/monolayer graphene SPR configuration, sensing performance changed with thicknesses of silver film and number of Ti₃C₂T_x MXene layers at Δn_bio=0.0012 RIU when the excitation wavelength is 632.8 nm. (a) Phase difference; (b) angle deflection

Fig. 5. Curves of phase difference changed with refractive index of medium by varying different thicknesses of silver film in the coupling BAK1 prism/silver film/Ti₃C₂T_x MXene/monolayer graphene SPR configuration when the excitation wavelength is 632.8 nm. (a) 30 nm; (b) 35 nm; (c) 40 nm; (d) 45 nm; (e) 50 nm; (f) 55 nm

Fig. 6. Simulated results at the sensing interface between Ti₃C₂T_x MXene and graphene. (a) Distribution of electric field intensity; (b) evanescent decay curve of electric field

Fig. 7. Comparison of the SPR sensing performances for different structures when the excitation wavelength is 632.8 nm