Line Renderer and Collider Question

hello there,

am trying to figure a way to make a lazer between 3 moving game objects and detect if any object intercept the lazer, I have the lazer already made as a line renderer between these 3 game objects. as far as I know , it could be done with adding a collider or casting ray between these objects , but unfortunatly I was not able to add the collider , niether get the ray cast correctly between the objects. I would appreciate an advice about this , or at least what method I should be using to accomplish this. oh and sorry for noob question :D