There's a lot of work in working antimicrobial sufaces - silver, copper, some interesting structural patterns, etc.

The problem is it's not particularly clear they work, and they are very expensive, and often a pain to clean.

https://en.wikipedia.org/wiki/Argyria perhaps?

And expense. Of course.

Better yet, why don't we have mobile hospital units. Rather than bringing all the sick people and disease into one place, why not go to the place of sickness. Perhaps it's economically not feasible, but I've always it made more sense.

Brass will do quite well and is a lot cheaper.