Royal Society of Chemistry, Analyst, 10(140), p. 3607-3615
DOI: 10.1039/c5an00363f
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Amperometric biosensors are often coated with a polymeric permselective film to avoid electroactive interferences by reducing agents present in the target medium. Phenylenediamine and phenol monomers are commonly used to form these permselective films in the design of microsensors and biosensors. This paper aims to evaluate the permselectivity, stability and lifetime of polymers electrosynthesized, using either constant potential amperometry (CPA) or cyclic voltammetry (CV), from naturally occurring phenylpropanoids in monomeric and dimeric forms (eugenol, isoeugenol, dehydrodieugenol and magnolol). Sensors were characterized by scanning electron microscopy and permselectivity analysis. Magnolol formed an electro-deposited polymer with a more defined three-dimensional texture in comparison with the other films. The phenol-derived films showed different permselectivity towards H2O2 over ascorbic acid and dopamine, likely to be related with the thickness and the compactness of the polymer. The CV-derived films had a better permeselectivity compared to the CPA-corresponding polymers. Based on these results, permselectivity, stability and lifetime of a biosensor for glucose were studied when a magnolol coating was electro-deposited. The structural principles governing the permselectivity of the magnolol-derived film are suggested to be mainly related to the conformational flexibility of this monomer. Newly-designed biosensors, coated with electropolymerized natural phenol derivatives may represent promising analytical devices for different application fields.