Electrochemical behaviour and analytical applications of a manganese porphyrin – silica hybrid film prepared by pulsed laser deposition

Abstract

Hybrid nanomaterials can have superior properties in comparison with individual components, sometimes greatly improving their optoelectronic activity. For this reason, modified carbon electrodes were obtained using a hybrid material composed of 5,10,15,20-tetra(4-tolyl)porphyrinato manganese (III) chloride (MnTTP) embedded in a silica matrix. The laser ablation deposition technique (PLD) has been used to immobilize the manganese porphyrin–silica hybrid on the surface of the carbon electrodes. The successful transfer of the manganese-porphyrin was evidenced by UV–Vis absorption spectroscopy. The PLD-deposited hybrid film was characterized using AFM and electrochemical methods (cyclic voltammetry and square wave voltammetry). The viability of this hybrid nanomaterial film as a redox mediator for the anodic oxidation and sensitive voltammetric determination of ascorbic acid in buffer solution (pH = 6.5) is described. The recorded anodic process is attributed to its oxidation to dehydroascorbic acid, with satisfactory catalytic current response and low non-Faradaic current.