A few years ago, I got my green card and had only my brazilian passport. Now I have an europena passport as well. Can I travel to Europe and come back to the US using my European passport or my green card is somehow attached to my brazilian passport?

Thank you.

I would recommend you to travel with original passport.. or when you return, immigration may not let you in easily.. .

Thanks. I'll take both just in case but will use the original one (brazilian).