clarify translation

Hello, i recently came across this quote that Anthony Burdain had tattoed on him. The quote was "i am certain of nothing." now he got it in ancient greek but there is no pictures of it online. The best i could come up with was "Βέβαιος εἰμι περὶ οὐδενός." , to get this translationi used ai and this was its reasoning

• Βέβαιος (Bébaios): means "certain" or "sure."
• εἰμι (eimi): means "I am."
• περὶ οὐδενός (peri oudenos): means "about nothing" or "of nothing."

now would this be right or is it impossible to get a direct translation to ancient greek ?