No. If I shut down my laptop, my hard drive is encrypted and keys are no longer in RAM (modulo a cold-boot attack, but that is only really useful for <30 minutes after shutdown without preparation).
You must have great reasons to be so paranoid. I am slightly jealous.
I mean the chances of putting the laptop to sleep and having your laptop stolen by someone with enough knowledge to obtain access to the keys in RAM to decrypt the hard drive - well, that would be an amazing story! Not to mention the fact that you have data that would be worth all of that trouble!