ZIF-90-Modified Terahertz Metasurface Sensor for Detecting Trace Acetone Gas With High Sensitivity and Specificity

Acetone gas can give rise to serious harm to the ecological environment and human health. In addition, acetone gas in the human exhaled breath can be used as an important biomarker for diabetes, lung cancer, lipid peroxidation, and other diseases. Therefore, detection of trace acetone gas is important for environment monitoring and disease diagnosis. Here, a four-split-ring-resonator terahertz (THz) metasurface sensor is proposed to detect trace acetone gas with high sensitivity, and the sample is fabricated using micromachining process. A new metal–organic framework (MOF) material zeolitic imidazolate framework-90 (ZIF-90) is modified on the surface of the sensor to improve its specificity for acetone gas. When the concentration increases from 10 to 100 ppm, the frequency shift of the sensor shows good linearity with the concentration. The minimum measurable concentration is 10 ppm, and the sensitivity is 0.1 GHz/ppm (or 10 ppm/GHz). This work paves a way for developing novel biosensors with high sensitivity and specificity, and it has potential applications in the fields of trace gas detection and disease diagnosis at early stage.