DNA molecule made of euros

I made this DNA molecule consisting of euro coins and notes.
I applied a sub surf modifier before applying the simple deform (twist) modifier.
I am quite happy with the result, except that the molecule looks quite edgy.
I hope someone could tell me how to smoothen it (smooth function did not work).
Please keep in mind in the answer that I am very new to Blender (just started today).

Many thanks in advance!