Fabrication of bisferrocenyl derivative grafted HTPB with high iron content and its application in dopamine detection

Abstract

In this work, we employed an efficient strategy to increase the graft percentage of ferrocene in hydroxyl terminated polybutadiene (HTPB) polymer framework. For this purpose, we use 5-chloro-2-pentanone to attach the two alkylferrocene derivatives to each other. In order to incorporate the obtained bis-alkylferrocene derivatives to the polymer backbone, the chlorine atom at the end of the coupling agent alkyl chain was converted to a silane group using the Grignard reaction. Finally, hydrosilylation reaction of as-synthesized silane derivatives and HTPB in the presence of Speier's catalyst (H2PtCl6) resulted in novel bis-ferrocene modified HTPBs with a variety of iron contents. The iron percentage, viscosity, and glass transition temperature of the novel bis-ferrocene modified HTPBs as essential parameters of polymer characterization were investigated. Obtained polymers are electro-active due to the presence of ferrocenyl groups. Additionally, unlike the virgin polymer (HTPB) they show optical properties. The final polymer was immobilized onto the bare glassy carbon electrode (GCE) surface using the cross-linking effect of terephthaldehyde (TFA) and fresh egg white (FEW). Electrochemical impedance spectroscopy (EIS) confirmed the successful immobilization of the polymer. The ability of the fabricated electrode to mediate dopamine (DA) oxidation was evaluated, and the results show the acceptable detection limits as well as linear ranges for the determination of dopamine using GC/BEFcHTPB/(TFA+FEW).