Meso-Tetra-(3,5-Dibromo-4-Hydroxydroxyphenyl) Porphyrin Copper (II) Self-Assembled Modified Gold Electrode Through l-Cysteine: The Preparation, Electrochemical Behavior and its Application

In this study, a sensor for the sensitive determination of ascorbic acid (AA) has been fabricated based on meso-tetra-(3,5-dibromo-4-hydroxydroxyphenyl) porphyrin copper (II) (T(DBHP)P-Cu) modified Au electrode through l-cysteine (l-cys). Firstly, l-cys modified Au electrode was prepared through self-assembled technology. Then T(DBHP)P-Cu was adsorbed on l-cys/Au through covalent binding. The fabrication process and electrochemical behavior of T(DBHP)P-Cu/l-cys/Au were studied by cyclic voltammetry and differential pulse voltammetry. The results showed that AA exhibited good electrochemical activity at T(DBHP)P-Cu/l-cys/Au. The oxidation peak current increased linearly with AA concentration in the range of 1.00 × 10−3–1.02 × 10−5 mol L−1 with a detection limit of 5.41 × 10−7 mol L−1. Additionally, the modified electrode could be applied to the detect AA in practical samples.