Not a/one jot
Definition 1 of 1
Pro Tip 1/3Slight Negation
The phrase expresses complete negation, emphasizing no impact or difference whatsoever. 
The critics' opinions mattered not a jot to the director.
Pro Tip 2/3Emotional Emphasis
Used to strengthen a statement emotionally, showing strong indifference or disregard. 
She doesn't care a jot about missing the party.
Pro Tip 3/3Colloquial Tone
Although understandable in most English-speaking countries, it's more casual and less formal. 
It won't make one jot of difference if you go there now.