17520
Understanding the binding mechanism of Dopa to TiO2 surfaces is therefore of considerable theoretical and practical interest .
 Chemical: Dopa; Chemical: TiO2
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: Dopa; Chemical: TiO2