Amplified detection of saccharide based on redox-poly(phenol-co-3-hydroxyphenylboronic acid) coupling with a redox cycling

Phenol and 3-hydroxyphenylboronic acid were electrochemically co-polymerized on a glassy carbon electrode in the presence of phenazine methosulfate (PMS), to form redox-poly(phenol-co-3-hydroxyphenylboronic acid). The as-synthesized phenylboronic acid bearing redox-polymer was characterized by UV–visible spectroscopy and cyclic voltammetry. The behavior of Fe(CN)63− catalytic reduction by electro-generated PMSred via a redox cycling was studied. With the addition of saccharide, a stable negative charged surface was formed owing to the generation of phenylboronate ester and then limited the access of Fe(CN)63− due to electrostatic repulsion. The electrochemical signal amplification of attenuated Fe(CN)63− was dependent on the concentration of saccharide. The dynamic ranges of the fabricated electrochemical sensor were 1–100 μM for d-fructose, 10–300 μM for d-mannose and 20–500 μM for d-glucose, respectively. The detection limits were ca. 0.3 μM for d-fructose, ca. 3.5 μM for d-mannose and ca. 7.8 μM for d-glucose, respectively.