Son threw up on iPhone 4 - Any ideas..... Won't turn on

Well as title, my boy threw up on the wifes iPhone 4, cleaned it up and it was working fine, for some reason the volume buttons were not working so I turned it off and on, then tried to do the latest 6.0.1 update, it came up with verifying update then turned off, and it now won't turn on!!

Any ideas?

I have tried pressing home and sleep/wake button for 10/20/30 seconds, when plugging it into a computer nothing happens, screen is dead.

Any suggestions?