Depending on reads you could consider checking to induce a bluff on the river.  It seems somewhat unlikely that you get another street of value from a worse hand, though if he just calls blindly then just bet obviously.  You're looking to get called by two pair or smaller sets, so a small-ish bet seems appropriate, a bit more than half pot maybe?

If villain is a weak station, this seems like a pretty easy bet as we won't really induce that often. You could consider check/folding, but that doesn't seem best as he'll be checking back worse hands which would have called more often than he'll have us beat I'd think with him having just called turn.

As for sizing, I guess something just over half pot would probably work here - we're trying to let him call with stuff like AKT, nut diamonds that made two pair etc. You could even consider going smaller - maybe $20 - if you think he might look you up as like as AK** that missed diamonds or T9. We assume he won't bluff-raise so you're bet/folding here, but I'm kinda not expecting him to raise.