27743
The as - developed TENG was systematically studied and demonstrated as a self - powered nanosensor toward catechin detection .
 Chemical: catechin
Given options, please tell me the categories of all the listed entity words.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
 Entities: catechin 
Answer:
 Chemical: catechin