Sleep mode

Can I put any Arduino in sleep mode (until an interrupt comes)? Not as watchdog timer.

Regards
Sven

Yes
https://playground.arduino.cc/Learning/ArduinoSleepCode

It doesn't help much to put an Arduino Uno to sleep, because everything else on the board continues to draw way too much power.

If you want to make your own "bare bones" Arduino, it will run for years on 2xAA batteries. See this tutorial.

Or, modify an Arduino Pro Mini by using a soldering pencil to remove the voltage regulator and LEDs to make the equivalent of a "bare bones" board.

Thanks for the answer,

Can I set a pro mini to sleep and shot off a shield through the board?

Regards
Sven

I suppose you mean "shut off". It would depend on the shield, but I don't know of any for the Pro Mini.