Teens create $13 door handle that kills 99.8% of germs on contact

I'm not sure that's a good reference :

"The article examines the connection between natural ultraviolet light (UV) radiation and the incidence of cancer in human beings."

This device uses artificial UV and then it's to activate titanium oxide on the handle (presumably some type of catalytic reaction is set up).

It's possible, on external handles, it could use natural UV but they state the main application is indoor, hence the capture of the door movement to generate the power for the UV light. Does sound rather clever.

However, as another poster has already said, the 'old fashioned' tradition of brass door knobs and general brass fixtures in toilets and even [very] old hospital beds has been shown to be very effective in killing bacteria. It was only after these were phased out in places such as hospitals, that resistant bacteria became a serious problem. (Though the time to disinfect seems to be much longer than this UV/titanium oxide version, so it could be an improvement in high traffic areas.)

Quite simply, I don't think this is setting up a binary choice between bacteria and cancer.