22761
Au - Au homodimer and Au - Ag heterodimer arrays produced using electron - beam lithography were investigated using confocal nonlinear optical imaging and spectroscopy .
 Chemical: Au - Au; Chemical: Au - Ag
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: Au - Au; Chemical: Au - Ag