Colorimetric Detection of Ferulic Acid by Nitrogen–Phosphorus Double-Doped Porous Metalloenzymes

Recently, nanozyme-based sensing platforms have attracted widespread attention due to their excellent performance in practical applications. In this paper, phosphorus-doped porous materials were synthesized by a one-step method and metal-doped with different metal salts. The results show that the iron-containing porous nitrogen-phosphorus material (FeNPC) has the best peroxidase activity. FeNPC catalyzes hydrogen peroxide to generate hydroxyl radical (•OH) which oxidizes colorless 3,3',5,5'-tetramethylbenzidine (TMB) to blue oxTMB. When the above system encounters ferulic acid, the blue product will be inhibited, and the color of the reaction solution will change, so ferulic acid can be detected by the colorimetric method. Ferulic acid is an antioxidant used in humans as an antibacterial and antiviral drug. The detection limit of this colorimetric sensor is as low as 1.3 nM. Compared with other detection methods, the colorimetric method is simple, fast, and cheap and has a good development prospect.