Although I have heard some wee bit about spraying a Boric Acid solution to keep ants away, and it might be somewhat effective while wet, when dry the ants would probably not pick any up and it would not be effective.
I have heard of making a bait of molasses, usually black strap, with a small quantity of Boric Acid mixed in which then does poison the ants. The recipe I recall is 1 tablespoon Boric Acid in 1 cup of molasses and placed outside away from where the ants were gaining entry into the house.
In the house Lemon Juice or Peppermint oil can be used to redirect the wee buggers back outside.
Keep in mind that Boric Acid can be a poison in humans and pets so due care in use and storage is necessary.