Tailoring the synthesis of V_0.25(Zr_1.75)C MXene for sensitive SERS quantification of ciprofloxacin antibiotics: spectroscopic and DFT investigation

In recent years, bimetallic MXenes have emerged as a promising class of 2D transition metal carbides, noted for their exceptional properties and tunable surface chemistry. This study reports the green synthesis of V_0.25(Zr_1.75)CT_x MXenes from its MAX phase using environmentally friendly etchants. We evaluated, experimentally and theoretically, the potential of the bimetallic MXene as an active surface-enhanced Raman scattering (SERS) substrate for detecting low concentrations of ciprofloxacin. The hybrid SERS substrate, leveraging coupled plasmonic effects, diffused Fermi levels, and enhanced inter-band charge transfer, achieved an outstanding enhancement factor on the order of 10¹⁰, enabling the detection of ciprofloxacin at an unprecedented limit of 1 × 10⁻¹⁴ M. The designed substrate exhibited a promising selectivity distinguishing ciprofloxacin from other possible interferents and achieved a high recovery rate of 98%. These findings highlight the significant role of bimetallic MXenes as a new and an effective class to develop SERS substrates for quantifying pharmaceutical compounds. This approach has promising implications for applications in biomedical diagnostics, environmental monitoring, and pharmaceutical quality control.