Design and fabrication of an ultra-sensitive Ta2C MXene/Au-coated tilted grating sensor

Abstract

Accurate evaluation of trace biochemical molecular signals by fiber-optic sensors is highly challenging. Recently, MXene, as one of the most promising 2D materials with unique optoelectronic properties and structural advantages, has attracted numerous concerns about the sensitization of optical fiber sensors. This paper proposed an innovative Ta2C MXene (Ta2C-M) sensitized Au-coated tilted fiber Bragg grating (TFBG) SPR sensor. We achieved the optimal deposition scheme for Ta2C-M by varying the laser induction time. The introduction of Ta2C-M brought a 23.3% increase in sensitivity and exhibited an excellent figure of merit (FOM=2586.11 RIU-1) and linearity (R2 =0.99903). Based on COMSOL, a 3D diversity analysis model was proposed, which validated the polarization response of the TFBG sensor, the electromagnetic gain of the Ta2C-M coating and enabled the fitting evaluation of the SPR behavior. The sensitization mechanism of the Ta2C-M coating was further analyzed utilizing energy band theory based on the Vienna ab initio Simulation Package (VASP). The assessment of two carcinogenic food additives, Saccharin and BHT, demonstrated the extreme SPR signal resolution and accurate trace detection performance (10-11 M) of the Ta2C-M/Au/TFBG sensor. These findings indicate that the proposed sensor will hopefully open new biotechnology, medicine, and food safety detection avenues.