A photochemical approach to anchor Au NPs on MXene as a prominent SERS substrate for ultrasensitive detection of chlorpromazine

As a novel two-dimensional (2D) material, metal carbide (MXene) has been identified as a hotspot research topic in the field of surface-enhanced Raman spectroscopy (SERS). Herein, we report the increment of SERS activity of titanium carbide (TiC) by incorporation of gold nanoparticles (Au NPs) by a facile photoreduction process for the detection of antipsychotic drug. TiC anchored with Au NPs produce a remarkable SERS enhancement by the synergistic action of chemical and electromagnetic mechanisms. The hotspots are formed in the nanometer-scale gaps between Au NPs on the TiC surface for the effective interaction with probe molecules. The proposed TiC/Au-NPs SERS substrate was employed for the detection of chlorpromazine (CPZ) with the wide linear range of 10(-1)-10(-10) M and the ultra-low limit of detection of 3.92 x 10(-11) M. Besides, the SERS effect of the optimized TiC/Au-NPs for the 532 nm excitation exhibits the enhancement factor in the order of 10(9) with the relative standard deviation of < 13% for the uniformity and < 8.80% for the reproducibility. To ensure the practical feasibility of the proposed TiC/Au-NPs SERS substrate, the spike and recovery method was used for the detection of CPZ in human biological fluids like urine and saliva. This work can open up a new approach to improve the SERS activity of MXene-based SERS substrate for practical applications, especially the determination of antipsychotic drugs in environmental pollution management.

Automated summary

In this study, the SERS activity of titanium carbide was significantly enhanced by incorporating gold nanoparticles. The TiC/Au-NPs substrate showed a wide linear range and low limit of detection for the detection of antipsychotic drug chlorpromazine. The synergy between chemical and electromagnetic mechanisms formed hotspots between the gold nanoparticles on the TiC surface, leading to effective interaction with probe molecules. The optimized TiC/Au-NPs SERS substrate exhibited high enhancement factor and good uniformity and reproducibility.