How and why can some metals like copper be antibacterial?
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The exact mechanism is unknown, but there are some theories.
One is that ~~positive~~ copper (or other metal) ~~ions~~ molecules interact with H2O2 within cells to form OH free radicals which interrupt cellular processes and cause them to lyse. Lysis is when a cell essentially self destructs and the cell membrane breaks apart spilling it’s guts out, destroying it. However, cells maintain a low concentration of H2O2, so this could only be partially responsible. ~~In water, the reaction of Cu+ with H2O would form H+ and OH-, not free radicals and (this statement was irrelevant)~~ observations of spraying cells in a mixture of liquid medium on surfaces in comparison to dry cells on surfaces showed that the dry cells died faster, which would seem to indicate that direct contact with the metal is responsible rather than free radicals in liquid medium.
The other prevailing theory is that the Cu+ ions interrupt cellular processes by bonding to cites normally occupied by iron ions (Fe+), which halts cellular functions needed for the cells to survive.
If you’re ready for a college level explainatiin, there is an oft cited paper here that you can read in its entirety. It was written in 2012, and I don’t know if there have been further developments because I’m not in college anymore and don’t have access to all the research databases to get full articles.
Don’t be intimidated to read scientific papers. When you come to terms or processes you don’t understand,look them up and keep following the rabbit hole until you do understand them, even if it’s just on Wikipedia.
Even if it takes you hours to get through even one sentence, there’s no shame in that, and it’s how you learn. I have a Master’s in Biomedical Engineering and was in a PhD program and that’s still how I read papers to this day. Wikipedia is a god send. I never would have made it through statistics without Wikipedia.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3067274/
Edit: typos and redundant phrases
Edit2: misremembered the difference between radicals and ions, so edited to clarify and make the response more correct.
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