Rapid Determination of Ochratoxin A in Black Tea Using Terahertz Ultrasensitive Biosensor

Abstract

Ochratoxin A (OTA), which is highly toxic and carcinogenic, is easily produced in cereal crops, dry herbs, and other foods under improper storage. Traditional detection methods, including high-performance liquid chromatography (HPLC) and enzyme-linked immunosorbent assay (ELISA), can detect OTA accurately, but there are many problems such as long period, high cost, and poor reproducibility. Therefore, developing a rapid, non-destructive, and highly sensitive method for OTA detection is essential. In this paper, we used a surface plasmon resonance (SPR) biosensor combined with terahertz (THz) spectroscopy to quantify OTA. As a result, the concentration range of OTA in acetonitrile solution was up to 0–20 pg/μL, with a detection limit of 1 pg/μL, which can meet the requirements for OTA detection in most foods. Further, we applied this method to black tea, and the detection limit was up to 1 pg/mg, which is 500 times higher than UV spectrophotometry, and completely meets the EU regulations. This study shows that the combination of terahertz spectroscopy and an SPR biosensor is a promising approach to achieve a simple, rapid, and low-cost method for trace substance quantification in foods and drugs.

Terahertz Fingerprint Metasurface Sensor Based on Temperature Variation for Trace Molecules

“…The proposed sensor can specifically identify trace substances. It provides a reliable approach for trace molecule sensing using THz technology [29]. In addition, the sensor can operate at multiple temperatures.…”