Specific detection of tartaric acid chiral isomers based on centrosymmetric terahertz metamaterial sensors

Tartaric acid is a common food additive with two mutually symmetrical chiral carbons, which is a very important class of four-carbon organic chiral sources. Centrosymmetric metamaterial sensors based on aluminum and polyimide were analyzed using CST microwave studio electromagnetic simulation software. The mechanism of the metamaterial resonance peak and the related electromagnetic field are analyzed. And the metamaterial was obtained by using coating and photolithography etching methods. The metamaterial has good detection performance and high sensitivity and can be used to identify tartaric acid chiral isomers (TACIs). The minimum detection concentrations of L-tartaric acid measured in the experiment were 0.001 g/ml. In addition, theoretical simulations of the crystalline cells of TACIs were also calculated using the density functional theory in quantum chemistry software. The absorption peaks of the TACIs simulation results are obtained, which are in general agreement with the experimentally measured results. Experimental results indicate that the metamaterial designed in this article can distinguish small differences TACIs, providing an effective method for both molecular identification and specific detection in biology and biomedical engineering.