Well if by love you are referring to family and close ones then yes it is all biochemical (not just pheramones and oxytocin and whatnot but also coded nucliec acids, etc.).
Remember there is a good biological reason, but it basically boils down to chemicals.
![Grin ;D](https://www.chemicalforums.com/Smileys/classic/grin.gif)
Can't have love without atoms.