Turn standard effect into shader for one material

Hello!

I want to turn edge detection effect from the standard assets into a separate material with shader in order to highlight certain objects. Usually you would just attach edge detection script to your camera and every object would be outlined (picture 1). However I need to highlight only one object so I tried to add edge detection shader to my material but now it looks very weird (picture 2).

I know that is possible to draw the needed object with another camera but that is not acceptable because of optimization reasons.

So, how can I use that effect for ONLY ONE object?