I understand you're trying to find scientific solutions to your question. However, here's a couple of outside-the-box additions.

I'm not a Creationist, but according to Genesis 1, the basic building block of everything in the universe, i.e. the first thing God created, is light.

Also in spiritual traditions, souls are conceived as beings of pure light.

And here's an interesting book title:

The Body Electric: Electromagnetism and the Foundation of Life by Robert O. Becker and Gary Selden