Highly Sensitive Detection of Carbendazim by Using Terahertz Time-Domain Spectroscopy Combined With Metamaterial

The rapid and sensitive detection of pesticide residue is essential for ensuring the food safety of consumers. However, there are many disadvantages for current approaches to detect pesticide residue, such as complex pre-treatment and low sensitivity. In this paper, we demonstrate a highly sensitive carbendazim detection method by using terahertz time-domain spectroscopy (THz-TDS) combined with metamaterial. The metamaterial composed of metal ohm ring arrays, is applied in detecting different concentrations of carbendazim. Resonant peaks of metamaterial move to a lower frequency as the concentration increases. The results illustrate that metamaterial can detect trace amounts of carbendazim, as small as 5 mg/L, which is about
$10^4$
times enhancement compared to the squash method for THz-TDS detection. It also means that metamaterial combined with THz-TDS is a potential new approach for food quality and safety control.