8042
Microfluidic biochips integrated using the substrates with arrays of nanowires and polydimethylsiloxane channels have been demonstrated to be effective for detecting antigens , and a detection limit of antigens at 0 . 2 mu g mL ( - 1 ) has been achieved , which is improved by a factor of 50 compared to that based on flat substrates without the nanowires .
 Chemical: polydimethylsiloxane
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: polydimethylsiloxane 
Answer:
 Chemical: polydimethylsiloxane