25000
We report the peptide - directed preparation and X - ray structural study of biofunctionalized Au nanoparticles ( NPs ) deposited on Ti surfaces .
 Chemical: Au; Chemical: Ti
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; Chemical: Ti