I need to execute a command for my system to search for new sd cards and to be able to execute it I need to execute it as root. Simply using sudo with the command does not work. This is not a question of how to execute an alias with sudo rights!

I want to know how to add an alias to the root user so I can execute it after using sudo -i.
I tried logging in to the root user and just adding the alias (which works fine). The only problem is that the alias disappears after I log out from the terminal.