Highly sensitive liquid refractometric sensing based on a square coreless fiber functionalized with few-layer Ti3C2Tx Mxene

Ti3C2Tx MXene, as a representative two-dimensional nanomaterial, has been recently receiving attention for constructing high-performance sensors. Herein, a square coreless fiber functionalized with Ti3C2Tx MXene layer is proposed and experimentally demonstrated for highly sensitive refractometric measurement. The refractometric sensor is designed by chemically depositing Ti3C2Tx film on the square coreless fiber, in which Ti3C2Tx film is employed for enhancing the hydrophilicity and promoting the adsorption capacity of molecules. Compared with pristine square coreless fiber, the sensitivity of the refractometric sensor is improved by more than 12% for liquids refractive index (RI) around 1.333. Moreover, the Ti3C2Tx modified square coreless fiber exhibits compact dimension, easy integration, low sample consumption, and good flexibility for enabling the accurate discriminating of small-scale RI changes of analytes. Our work provides a promising and effective platform for general ultra-low concentration analytical detection, which could be extended for biochemical sensing, photocatalysts, and photovoltaic applications.(c) 2023 Optica Publishing Group under the terms of the Optica Open Access Publishing Agreement