Composite of Polydimethylsiloxane(PDMS) and 2D Vanadium Carbide MXene (V2CTx) as a Flexible and Free-Standing Surface-Enhanced Raman Scattering Substrate

Flexible Surface enhanced Raman scattering (SERS) substrates have gained great interest owing to their easy handling and ability of on-site real-time diagnosis of multiple analytes in practical application as compared to rigid substrate. Here, we have synthesized two-dimensional (2D) vanadium carbide (V 2 CT x ) MXene. Composite of Polydimethylsiloxane (PDMS) and V 2 CT x MXene designed to obtain transparent and flexible SERS substrate. The SERS study reveal that PDMS/ V 2 CT x composite substrate can detect 10 ⁻⁵ M of Methylene Blue (MB) dye. Further we have studied how external strain i.e. bending or stretching applied on the PDMS/ V 2 CT x composite substrate can affect the SERS signal. It was observed that flexible composite substrate shows maximum 6.7 times of Raman enhancement for 10 ⁻⁵ M MB dye for negative bending of substrate. The SERS enhancement explained by charge transfer process between functional groups (-OH, -F, -CI) present on V 2 CT x MXene's surface and dye molecules. This result encourages the development of flexible MXene-based SERS substrate as a wearable device in biomedical research or environmental application in the near future.