I've had something on my mind for the last couple of weeks and I'm just going to throw it out there into the Mastodon hive mind and see if anyone knows anything. Sorry to the few people that I'm tagging here, just thought you would be the most likely to know.
I've had some 405nm LED light bulbs since before the pandemic. Long story short, I beta tested them for a company for HomeKit compatibility, but while I had them on hand my wife and I bought some Petri dishes, took some swabs from various places and did a science experiment with our kids. At the power and distance that I used them(in place of downlights at ceiling height) they did not kill 100% of the growth on the plates, but it was clear that they did have an effect.
With all of the talk around 222nm, I haven't really heard anyone talking about 405nm in a long time. There was a report from 2021 about 405 and COVID:
https://www.nature.com/articles/s41598-021-97797-0
Has anyone tried a test of 222 AND 405 together? I couldn't come up with any results, so I suspect not.
Does anyone know if anyone's producing products around 405nm currently? The company I have 4 bulbs from was bought out by another company since then, and when I inquired about them they said they still have a few in stock, but I don't think they're producing them any more. A search only produced a bunch of "rave" lights that include 405nm, but aren't centered around it, so I'm unsure if they'd be effective.
@BE I don't have the time to pull the references off of That Other Site right now, but I did a big workup of a paper on 222 nm that showed that SARS-CoV-2 was far less durable than the bacteria they were using vs. 222 nm light, by a factor of ~10 or so IIRC?
Presumably this is due to the lack of cell walls between nucleic acids and the medium. I would be interested to see if 405 nm had the same effect!