Synthesis of vanadium carbide MXene with improved inter-layer spacing for SERS-based quantification of anti-cancer drugs

The development of rapid and efficient spectroanalytical protocols to detect bioactive drugs in aqueous samples is linked with the evolution of new generations of nanostructured materials. The 2D vanadium carbide (V₂CT_x) family of MXenes has been proved to be a promising material owing to its excellent plasmonic effects, short-range charge transfer (CT), and covers a wide variety of applications, especially in the fields of sensing and optics. For several years, research is focused on the stability and inter-layers spacing of a few-layered V₂CT_x in colloidal states. In this work, the synthesis and characterization of vanadium carbide sheets using a soft condition approach were reported. The delamination with the triethylamine (TEA) intercalant resulted in deceased interlayer spacing of 8.13 Å and enhanced the shelf life by up to six weeks. The synthesized highly stable MXene was treated with self-assembled silver nanoparticles (AgNPs) to fabricate a hybrid material as a potential surface-enhanced Raman scattering (SERS) substrate for the detection of ultra-trace quantities of anti-cancer drug gemcitabine (GMC). The developed approach showed an unprecedented limit of detection of 10^-12 M with a wide dynamic range of 10^-4-10^-12 M. The MXene-based SERS sensor has achieved a Raman signal amplification corresponding to an enhancement factor of 10⁹, with high sensitivity and reproducibility.