Highly Sensitive Surface Plasmon Resonance Sensor Modified With 2D Ti₂C MXene for Solution Detection

Two-dimensional (2D) Ti
₂
C MXene has great prospects in many fields of biotechnology and biosensing owning to their highly active 2D surfaces, in this work, we demonstrate a high sensitivity surface plasmon resonance (SPR) sensor modified by the 2D Ti
₂
C nanosheets overlayer. Our experimental results show that the performances of the SPR sensor are closely related to the thickness of 2D Ti
₂
C nanosheets, and the proposed design gives the wavelength sensitivity of 3579.6 nm/RIU, which are 79% higher than the SPR sensor without Ti2C overlayer. In addition, the Ti
₂
C covered SPR sensor is capable of detecting low concentrations of heavy metal ions, our results show that the maximum concentrate sensitivities are 3.788 nm/μg/L, 5.308 nm/μg/L and 3.233 nm/μg/L for Pb
²⁺
, Cr
²⁺
and Hg
²⁺
ions, and the corresponding detection limits are 79.2 ng/L, 56.5 ng/L and 92.8 ng/L, which are lower than the international medical standards. Our results pave the way to realize high sensitivity biosensor and environmental pollution detection.