Check of all libraries you use the license - many are MIT, Apache or BSD licensed which basically means you can do what you want with it. No need to release source code or so.
Also (L)GPL software is no problem, they just require you to release the source with any changes (and if it's a library released as LGPL, that just accounts for that library, not the rest). You can freely sell your product.
If you want to be really sure, ask your university's legal department for their opinion. If they say you're OK, and you're not, at least it's not your fault.