I recommend a portable toothbrush sterilizer.

I recommend the portable Li & Cook UV LED toothbrush sterilizer.

My younger sibling gave it to me as a gift a long time ago.

At first, I used it by just replacing the batteries, but later I found out that it could also be charged via USB.

Currently, I use it after brushing my teeth at work, simply sterilizing it for about two hours. Since it is portable, I take it with me when I travel as well. There is also a space to store interdental brushes, so I keep them in there as well.