There are two ways to detect bad sectors in Linux: you can use the disk utility (gui), or you can use the badblocks command to check your hard disk for bad sectors:

sudo badblocks -v /dev/{device}

That should answer the question but for anyone else interested in how to mark them it can be done with 2 simple commands...

You add the bad blocks to a file...

sudo badblocks /dev/sdb > {/dir/to/filename}

and then tell fsck to mark these as unusable with ...

sudo fsck -l {/dir/to/filename} /dev/{device}