A simple paper-based colorimetric biosensor based on immobilized tyrosinase and 3-methyl-2-benzothiazolinone hydrazone (MBTH) was developed for assessing total polyphenol content (TPC) of various green tea beverages. The patterned biosensing zone of the paper-based biosensor showed a sensitive response to catechin (a typical green tea polyphenol) by generating pink color adducts that can be captured for further color image analysis using a scanometric method. This color change can be connected to the TPC of the samples. The analytical performance of the biosensor in scanometric set-up was optimized. The biosensor showed a response time of 13 min in the linear range between 0.08-1.03 mM of catechin (r = 0.9979). The detection limit (LOD) of the biosensor was 0.071 mM while reproducibility was found at 3.11% RSD (relative standard deviation). TPC of green tea beverages was assessed by the biosensor, and the results were in accordance with the UV/Vis spectrophotometric method.

基于固定化酪氨酸酶和3-甲基-2-苯并噻唑啉酮（MBTH）的一种简单的基于纸的比色生物传感器被开发用于评估各种绿茶饮料的总多酚含量（TPC）。纸质生物传感器的带图案的生物传感区域通过生成粉红色加合物显示出对儿茶素（一种典型的绿茶多酚）的敏感反应，可以使用扫描测量方法捕获该粉红色加合物以进行进一步的彩色图像分析。这种颜色变化可以连接到样品的TPC。优化了生物传感器在扫描设置中的分析性能。该生物传感器在0.08-1.03 mM儿茶素之间的线性范围内显示13分钟的响应时间（r = 0.9979）。生物传感器的检出限（LOD）为0.071 mM，而重现性为3.11％RSD（相对标准偏差）。