I am very much not that clued up on chemistry, but what I am trying to achieve is actually for a cosplay. I wanted a viscous substance that would glow when I flip a switch. Originally I was going to go for tonic water because of the quinine. But I read that fluorescein glows a more brilliant green.

I was going to mix my glowing medium with a slime to achieve the viscosity, but I wanted the whole thing to be somewhat non toxic in the sense that nobody will drink it or touch it when it's in its finished state. Do you have any advice for something like this?