Development of Paper Based Sensor for the Determination of Total Phenolic Content in Green Tea Beverages

Tea (Camellia sinensis L.) is one of the most popular beverages around the world. Tea was reported to contain polyphenols, which play a key role in treatment and preventing of many diseases such as cardiovascular and neurodegenerative diseases. Thus, the content of polyphenols could be used as indicator for the quality of tea. Here, the development of low-cost, portable and disposable sensor for determination of green tea quality is described. The sensor was based on immobilization of sodium metaperiodate (NaIO4) in paper as a test strip. NaIO4 was coupled with 3-methyl-2-benzothiazolinone hydrazone (MBTH) as coloring agent. The polyphenols sensor has response time 9 minutes and a linear range at 25-300 ppm, with a detection limit 10.2 ppm toward catechin. The reproducibility of sensor was 0.628% with life time within 20 days when stored at 4oC. The total polyphenol content in green tea beverages were determined by the sensor, and the results were in agreement with the Folin Ciocalteu assay. The developed sensor can be used as a tool for determination total polyphenol content in tea samples.