Electrosynthesis and electrochemical characterisation of phenazine polymers for application in biosensors

Abstract

A comparative investigation has been undertaken of the electrosynthesis and electrochemical properties of three different electroactive polymers on carbon film electrode substrates: poly(neutral red) from the phenazine dye neutral red, and poly(methylene green) and poly(methylene blue), from the corresponding phenothiazine dyes. The formation of the radical cation at different potentials and the chemical structures of the monomers both influence the electropolymerisation process of the three polyaromatic dyes. Of the three, poly(neutral red) is shown to have the best adhesion at carbon film electrodes. The influence of the electrolyte and pH on film growth and on electrochemical properties was investigated. The formal potential decreased linearly with increase in pH, in the pH range from 1 to 7 for all three polymers. The modified electrodes were also characterised by electrochemical impedance spectroscopy. The bulk and interfacial characteristics of the two phenothiazine polymers were similar and oxygendependent, but different to those of the phenazine polymer, poly(neutral red), which were not significantly influenced by the presence of oxygen in solution. Perspectives for use in electrochemical biosensors are indicated.

Amperometric Sensor for Detection of the Reduced Form of Nicotinamide Adenine Dinucleotide Using a Poly(pyronin B) Film Modified Electrode

“…After electropolymerization, an adherent polymer observed on the GCE. The similar results were obtained in the electrochemical polymerization of methylene blue and methylene green [52]. Karyakin et al [53] reported that the polymerization of monomer containing one or two tertiary amine groups was taking place through tertiary amine.…”

“…Moreover, as polymerization occurs, more tertiary amine groups become nitrogen bridges and these bridges become electroactive similar to those in polyaniline and poly(thionine) films [54,55]. PyB monomers were able to form an electroactive polymer by anodic oxidation from acidic aqueous solutions similar to poly(methylene blue) nor poly(methylene green) since its chemical structure resembles with methylene blue and methylene green [10,52,53]. The structure of poly(PyB) film might similar to the hypothetical structure proposed for poly(methylene blue).…”

Preparation and characterisation of poly(3,4-ethylenedioxythiophene) and poly(3,4-ethylenedioxythiophene)/poly(neutral red) modified carbon film electrodes, and application as sensors for hydrogen peroxide

“…The behaviour is similar to that observed for PNR/CFE [33]. In order to elucidate whether some fragments of oligomers of the two polymers are present on the electrode surface, an experiment was performed by dipping the modified electrodes in buffer overnight.…”

Desenvolvimento de eletrodo modificado com polímero de azul de metileno para a determinação eletroanalítica de glifosato

“…A síntese de polímeros condutores pode ser realizada por meio da oxidação ou redução química ou eletroquímica de uma substância e podem apresentar a condutividade elétrica de um metal [5,42]. Assim, a escolha do método de síntese é importante uma vez que influencia na qualidade e propriedades finais do polímero.…”

“…Em particular, a modificação da superfície de eletrodos por eletropolimerização de várias fenazinas, fenoxazinas e fenotiazinas foram relatadas na literatura [42,43,[47][48][49].…”