Electrochemistry and determination of epinephrine using a mesoporous Al-incorporated SiO2 modified electrode

The potential application of Al-incorporated mesoporous SiO₂ (denoted as Al-MCM-41) in electrochemistry as a novel electrode material was investigated. The peak currents of K₃Fe(CN)₆] remarkably increase and the peak potential separation obviously decreases at the mesoporous Al-MCM-41 modified carbon paste electrode (CPE). These phenomena suggest that the mesoporous Al-MCM-41 modified CPE possesses larger electrode area and electron transfer rate constant. Furthermore, the electrochemical behavior of epinephrine (EP) was investigated in different supporting electrolytes such as 0.01 mol L⁻¹ HClO₄ and pH 7.0 phosphate buffer. It is found that the mesoporous Al-MCM-41 modified CPE exhibits catalytic ability to the oxidation of EP due to remarkable peak current enhancement and negative shift of peak potential. The electrochemical oxidation mechanism was also discussed. Finally, a novel electrochemical method was proposed for the determination of EP, which used to determine EP in urine samples.