Functionalized MXene (Ti₃C₂T_X) Loaded with Ag Nanoparticles as a Raman Scattering Substrate for Rapid Furfural...

Furfural is an essential compound that contributes to the distinctive flavor of sauce-flavored Baijiu. However, traditional detection methods are hindered by lengthy and complex sample preparation procedures, as well as the need for expensive equipment. Therefore, there is an urgent need for a new approach that allows rapid detection. In this study, we developed a novel surface-enhanced Raman spectroscopy (SERS) substrate by constructing MXene (Ti₃C₂T_X) @Ag nanoparticles (Ag NPs) through an electrostatic attraction method. The MXene (Ti₃C₂T_X) @Ag NPs were successfully fabricated, with adsorbed NaCl-treated Ag NPs uniformly absorbed on the surface of MXene (Ti₃C₂T_X), creating high-density distributed SERS "hot spots". The prepared substrate demonstrated excellent sensitivity, uniformity, repeatability, and long-term stability, with a low detectable concentration of 10^-9 M for R6G (Rhodamine 6G) and an enhancement factor of up to 7.08 × 10⁵. When applied for the in situ SERS detection of furfural in Baijiu, the detection limit was as low as 0.5 mg/L. Overall, the proposed method offers rapid, low-cost, and sensitive quantitative analysis, which is significant not only for detecting furfural in Baijiu but also for identifying hazardous substances and distinguishing between authentic and counterfeit Baijiu products.