You have to do this in one fight, not in one combo!
You need to unlock the following gadgets before attempting this achievement. The order does not matter.
Quickfire gadgets you can use are:
for the electro gun
for the Batclaw
for the explosive gel
(double tap) for the freeze bomb
(bouble tap) for the batarang
video credit: LetsPlay Community
Hope this helps!
Any improvements? Plese let me know in the comments below!