Speaking from experience, my previous percula liked bloodworms. In fact, it's the only food that it ate. Brine shrimp is good too.
I would be really careful with perculas. It is really hard to get a very good speciment, as they are normally handled very roughly, the false ones at least. Whenever I go to my LFS, the two of them, have the same problem. Percula clowns with Brooknella. I have tried keeping false perculas twice. Both didn't happen because of Brooknella.
I don't want to scare you, but this might be what's happening to you. When I first got my clowns, both of them ate (best speciments from the lfs). Then one stopped. The other was still eating. Thinking that it's only a momentary thing, I ignored it. Later on the other got infected. Both fish don't eat, both died of brooknella.
Try to read some of the post about Brooknella. I know there's a cure, but although I went to three different LFS, all three of them don't have it. I forgot the name of it, but it is there on the posts.
Try to read some of the posts about Brooknella. Keep observing your fish. If in two days it is still not eating. Personally, I would take precautionary action by putting it in q-tank and starting with treatment.
The best of luck,
stupid_naso