Surface-enhanced Raman spectroscopy sensing of Huangjiu's total antioxidant capacity utilizing polyoxometalate-based frameworks nanozymes

The ability to accurately assess the total antioxidant capacity (TAC) of Huangjiu is essential for the comprehensive assessment of its nutritional and medicinal benefits. Consequently, developing a rapid, sensitive and specific analytical methodology to determine TAC is an urgent research need. In this work, we explored the potential of a one-step solvothermal process, leading to the synthesis of polyoxometalates-metal-organic frameworks (POMs-MOFs), H3PW12O40 (HPW)-CuBTC materials, which possess a high surface area and considerable active sites. Our results demonstrated that HPW-CuBTC materials exhibit remarkable surface-enhanced Raman scattering (SERS) activity, capable of detecting 10–8 M methylene blue (MB). SERS activity was attributed to both the localized surface plasmon resonance (LSPR) and charge transfer (CT) synergistic enhancement mechanisms. Furthermore, HPW-CuBTC materials exhibited peroxidase (POD)-like activity, with a catalytic mechanism involving a synergistic catalytic effect between HPW and CuBTC. We developed a catechin sensor based on the POD-like properties of HPW-CuBTC, with a linear range from 4 μM to 8 μM (R2=0.98). Additionally, we utilized the HPW-CuBTC materials to construct a TAC sensing platform in Huangjiu. This work introduces new technologies and methodologies for rapid trace detection of TAC in Huangjiu, providing a valuable tool for evaluating its nutritional and medicinal benefits.