Anyone can try to sue for anything at any time. However, such actions are civil suits and not criminal matters. Only the police and prosecuting attorney (person working for the relevant government agency) may file criminal charges. In general for a civil case you have to prove that you were damaged and that the other person was in fact lying.
These statements do not constitute legal advice. They are meant to be general in nature, for any specific legal questions you should always seek the counsel of an experienced attorney.
To sue for defamation, there has to be a false statement made about your character or ability to do your job, it has to be communicated to a third party (i.e. someone besides you and the person talking) and you have to have suffered some sort of economic/monetary damages. So if it only made things awkward for you with your boss or just made you mad, then there is no case. If you lost your job or had to pay a penalty at work because of it, then you may have a case.