I just installed go to /usr/local/go, and in ~/.bashrc added this line:

export PATH=$PATH:/usr/local/go/bin

Now go works from the command line, but sudo go gives me:

$ sudo go

sudo: go: command not found

~

$ sudo echo $PATH

/usr/lib/lightdm/lightdm:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/home/benjamin/algs4/bin:/usr/local/go/bin