Immobilization of phenol-containing compounds via electrochemical activation of a urazole derivative

We introduce an efficient method for the immobilization of phenolic compounds, based on 1,2,4,-triazoline-3,5-dione (TAD), which selectively reacts with phenolic compounds at the alpha position to the phenolic hydroxyl group, ensuring intact phenol functionality, and therefore, maintaining the biological activity of the phenolic compound. We prepared self-assembled monolayers on gold that presented urazole (the reduced form of TAD) as the terminal group and which were activated electrochemically without treatment with chemical oxidants, allowing on-demand activation and in situ immobilization of the phenolic compounds. We examined the immobilization of various phenolic compounds and verified the surface chemistry using electrochemistry and mass spectrometry. The proposed method is simple and straightforward and does not require complicated protocols and reagents, and thus, it can be a general and practical platform for the immobilization of phenol-containing molecules on the surfaces of various materials.