Do No-Follow backlinks work in SEO?

No follow links don't pass any link juice, they don't help increase PageRank and doesn't help the site/page it's pointing to rank any higher. Is this mean? Well no, not when you consider the alternative The no follow tag was introduced to help cut down on and prevent spam. You see, when people learned of the importance of links "pointing" to a site, some sites went overboard and started getting them by any means necessary. They would buy them, pay people to mass link to their site, abuse comments (by spamming their links), etc. just so they could increase their search engine ranking.

It is important to say here that adding "Do not follow Links"  on your landing pages suggest to search engine platformS that you understand search engine languages, therefore can be penalized  for some search engine optimizations that ordinarily should be ignored by them.