“…In 2022, Zhu et al 24 proposed a metamaterial sensor composed of a graphene four-open square ring and a golden hemisphere, and combined with THz-TDS technology to identify four amino acids of proline, glycine, arginine and methionine, and the recognition accuracy reached 100%. In 2022, Hu et al 25 designed a terahertz enhanced metamaterial absorber based on the electromagnetic theory and applied it to the effective detection of benzoic acid samples. The detection limit of benzoic acid was 2.36 × 10 −5 g ml −1 , which promoted the rapid detection of benzoic acid additives in food and was of great significance for promoting the detection and analysis of trace additives in food.…”