Short answer: No, it will not impact you negatively.
Long answer: Unicode is just a representation of characters from U+0000 to U+10FFFF. Nothing more. Google is able to understand that just as well as any other standard represention of characters. If you asked "how SEO friendly unicode URLs are", well that would be a matter of taste, language and target market. Amazon Japan uses unicode characters in their URLs due to nonexistent and/or unreadable URLs in ASCII representation. Same goes for some non-latin character languages such as Arabic, Hebrew, Farsi, Chinese, etc.