'sudo open' command doesn't propagate privilege

I have an application folder (.app) which requires root privilege for capturing network packets. I tried to execute with 'sudo open foo.app' but came back with permission denied error.

So I changed the directory down to foo.app/Contents/MacOS/ and run the actual binary with sudo command instead. The binary run fine without permission problem.

I did 'sudo bash' to create a root shell and run 'open foo.app', it still came back with permission problem.

I am not a Mac experience user, is the 'open' command supposed to stop the root privilege?

Many thanks
Joe