Million-Nasse’s reaction is specific for the amino acid:
Millon’s Test: The phenol group  of phenylalanine and tyrosine containing proteins, when heated with mercuric sulfate in sulfuric acidand sodium nitrite (or, mercurous and mercuric nitrates in nitric acid) form red colored mercury phenolate.
Reference: Vasudevan 7th  ed, pg 31
Tryptophan
Tyrosine
Phenylalanine
Arginine