7422
Here is shown an alternative easy and inexpensive synthetic approach to a SERS - substrate comprised of gold nanotubes obtained by the sputtering onto polycarbonate track - etched membranes used as template .
 Chemical: polycarbonate
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: polycarbonate