15568
The near - infrared luminescent agent was a ruthenium complex that was directly entrapped in the silica shell to provide photoluminescence enhancement and to make it highly photostable as it was protected from the surrounding environment .
 Chemical: ruthenium; Chemical: silica
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
Answer:
 Chemical: ruthenium; Chemical: silica