Look into liquid bandages. It's exactly this and is already available at every drug store. Comes as a little nail polish-style bottle + brush.

It sterilizes and seals, pretty much replacing my whole bandaid kit I used to keep in my pocket book.

I'll even buy a bunch at a time and give them out to friends. It's so useful yet no one knows about it.

(That said, you won't be sealing bullet wounds or giant gashes with it)