In Cologne, Anthony wrote about manipulation on a molecular scale (14)
I believe the answer is:
'manipulation on a molecular scale' is the definition.
The definition suggests a singular noun which matches the answer.
'in cologne anthony wrote' is the wordplay.
'cologne anthony' can be anagrammed to 'NANOTECHNOLOGY'.
Though, I'm unsure how this is indicated.
'about' acts as a link.
Can you help me to learn more?