Terahertz Metamaterial Sensor for Sensitive Detection of Citrate Salt Solutions

Abstract

Citrate salts (CSs), as one type of organic salts, have been widely used in the food and pharmaceutical industries. Accurate and quantitative detection of CSs in food and medicine is very important for health and safety. In this study, an asymmetric double-opening ring metamaterial sensor is designed, fabricated, and used to detect citrate salts combined with THz spectroscopy. Factors that influence the sensitivity of the metamaterial sensor including the opening positions and the arrangement of the metal opening ring unit, the refraction index and the thickness of the analyte deposited on the metamaterial sensor were analyzed and discussed from electromagnetic simulations and THz spectroscopy measurements. Based on the high sensitivity of the metamaterial sensor to the refractive index of the analyte, six different citrate salt solutions with low concentrations were well identified. Therefore, THz spectroscopy combined with a metamaterials sensor can provide a new, rapid, and accurate detection of citrate salts.

Design of high-Q and high-sensitivity terahertz metamaterial sensors for trace detection

“…It can be seen that the relationship is nonlinear, with the increase of the thickness of the analyst, Δf gradually increases and eventually saturates around h = 30 μm, implying the electric field can extend up to 30 μm in the dielectric analyte. This is somewhat different from previous studies [23,28,29] where the saturated frequency shift occurs around h = 15 μm due to the different metamaterial sensor structure. Therefore, a saturated thickness of 30 um is used to investigate the sensitivity of the metamaterial sensor.…”

Evaluating Hyperbolic Dispersion Materials for Cancer Detection

“…The average sensitivity for refractive index variation (RI) was around 4146 intensity units/RIU, and the highest array sensitivity value was 4179 intensity units/RIU. Experimental results demonstrate that the system was able to monitor HER2 at a known concentration of 3 ng/mL, which shows credible potential for future bioassay diagnosis [ 1 , 3 , 25 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 , 48 , 49 , 50 , 51 , 52 , 53 , 54 ].…”

Exploring the Application of Multi-Resonant Bands Terahertz Metamaterials in the Field of Carbohydrate Films Sensing

“…Terahertz spectroscopy is an important means for investigating the characteristics of biomolecules, such as carbohydrates, proteins, and DNA [ 1 , 2 , 3 , 4 , 5 , 6 ], as their vibration and rotation frequencies fall within the terahertz frequency range, allowing them to exhibit certain absorption properties in this band [ 6 , 7 , 8 , 9 ]. Despite the potential of terahertz waves to measure biomolecules, their limited interaction makes it difficult to achieve high sensitivity detection of target biomolecules and distinguish multiple biomolecules [ 10 ].…”