Can you say "Il n'y a aucune de bananes" or would it be "Il n'y a aucun de bananes"?
Would "aucun" have to agree with the feminine noun "banane"?
There are three possible forms: "il n'y a pas de banane" (singular, "il n'y a pas de bananes" (plural) or "il n'y a aucune banane" (singular). The meaning is different:
Implies "there is no banana (in this recipe)" or something similar; no banana as ingredient.
There are no bananas (here).
There isn't any banana (here).
No native speaker but your turn "il n'y a aucune de bananes" does not sound idiomatic. So to a question of the form
A/ Est-ce qu'il y a des bananes ?
some possible answers include
B/ Il y en a. Il n'y en a pas.
C/ Il n'y a pas de bananes.
D/ Il n'y a aucune banane.
E/ Il n'y en a aucune.
F/ Aucune.
G/ Oui/Non.
H/ On n'a aucune banane de bonne.
Il n'y a aucune banane : yes, aucun has to agree with the feminine noun banane — without the de word.
In fact, aucun (or aucune) has the meaning of zero and is used as a number : il y a une banane, il y a deux bananes, il y a zéro banane.
(Or with numbers: il y a 1 banane, il y a 2 bananes, il y a 0 banane).
Except that aucun/aucune needs a negative prefix (ne before a consonant or n' before a vowel as here): il n'y a aucune banane.
As if zero was not enough to say you have no banane :^)