Electrocatalytic activity of manganese tetra 4-aminophenyl porphyrin in the presence of graphene quantum dots

Abstract

A manganese tetra 4-aminophenyl porphyrin (MnTAPP) was synthesized and attached to graphene quantum dots (GQDs) via covalent and π-π interaction to give [email protected] and MnTAPP--GQDs, respectively. There was an increase (using dynamic light scattering and transmission electron microscopy) in size of the GQDs in the presence of the porphyrin due to aggregation. The porphyrins in the absence and presence of GQDs were then adsorbed onto a glassy carbon electrode using drop and dry method. The electrochemical behavior was tested by cyclic voltammetry and chronoamperometry towards hydrazine. Both methods of combining MnTAPP with GQDs improved the activity of the electrocatalysis compared to individual components. [email protected] showed better catalytic rate constant of 4.36 × 102 Ms−1 and lowest LoD of 0.0023 mM followed by MnTAPP--GQDs. Furthermore, the sensor showed good selectivity in the presence of interfering analytes. All probes showed good stability.