A detection system for determining the quantity of amino acid in a sample stream is provided based on the reaction of a buffer at a pH level from 10 to 11, with a reagent Ru(bpy)3 3+, which is generated electrochemically on site. The detection system is further characterized by immediate luminescence upon reaction of the buffer in the pH range containing amino acid, with the reagent Ru(bpy)3 3+. The detection system is capable of not only immediate detection of the quantity of amino acid in a sample stream, but even in very low concentrations