the only product ive ever found to glow under UV light is IBD intense seal, from what i can gather this is because it has brightners in it, so when you go in daylight the small amount of UV from the sun makes them look brighter. but when they go under intense Uv light they glow!!!
Ive never known a L&P or Gel system to do this. only over white tips.
Most acrylics contain an ingredient called an optical brightener although acrylic overlays generally don't glow under a black light (the ultraviolet lights you find in nightclubs).
The product that glows is the UV Block used over the top of acrylics that is applied to stop them from yellowing; a common problem with some overlays. It is a type of top coat applied as varnish that contains these optical brighteners, its job is to block UV light so that it does not affect the overlay beneath it.
There are also many high gloss UV cured gel top coats that contain these optical brighteners which will also glow under a black light.
I think LilDee has it right. In my "other" profession I teach classes on Health and have this great kit with a black light that will show the "germs" still left on the hands after they have been washed (it's lotion that has glow in the dark pigment). Well, anyway, whenever I do this activity all the white acrylic on the gals with enhancements will glow ~ everytime. I think it's because white "glows" under black light.