Can UVC light detect germs?

No. UVC light can not detect germs. UVA light can.

Also known as long-wave ultraviolet light (or UVA light), blacklight causes specific materials to "fluoresce" or radiate visible light in total darkness. ... Since certain bodily fluids can transmit certain sickness-causing bacteria and viruses, a blacklight can also help you detect potentially threatening bodily fluids.