TBH, in nanotech's case, I'm not even sure it's Misapplied Phlebotinum, as just hijacking a hyped term for stuff it was never meant to mean.
The original idea for nanotechnology was for nano-scale machines. Maybe not tiny sentient robots, but at least stuff capable of self-assembly or self-replication (see, gray goo) or performing some non-trivial manipulation. A ribosome would be a proper nano-tech example, or at the very least some smart protein could reasonably be called nanotech in the original sense.
Now we see it used for just about anything that uses really small particles, e.g., I kid you not, mayo or paints, for fork's sake. Or even plain old chemistry. Dying a t-shirt with titanium dioxide, a.k.a. the pigment "titanium white", isn't some smart nanotech, it's just using a dye, fer crying out loud. It's not even some really smart new mollecule, it's a simple anorganic white pigment, which they're using, you know, dye a t-shirt white. Whop-de-frikken-do.
And, oh, looky, the ability for it to destroy living cells when exposed to light, by creating free radicals, is also nothing new. We knew that since, you know, using it in UV blocking lotions. The particles there have to be coated in silica, because otherwise they do a whole number on your skin and may even cause DNA damage, i.e., it can be carcinogenic.
So let's recap: they're using a simple anorganic white dye that kills cells, to dye t-shirts white and kill bacteria on them. It's about as related to nanotech as when you use water to dissolve some salts. I.e., not really. It's just chemistry.
The term nanotech may have once been effectively Phlebotinum, but in the meantime it's been hijacked by marketroids and PR folks into something completely meaningless. Anything that has any particles in it or any kind of mollecules, tada, now is nanotech. Your mayo is nanotech, the paint on your walls is nanotech, and the water you drink is nanotech.
Bah...