An Enzyme Free Potentiometric Detection of Reducing Sugars Based on a Poly(3-hydroxyphenylboronic acid-co-phenol) Molecularly Imprinted Polymer Modified Electrode

An enzyme free potentiometric sensor for reducing sugars (glucose and fructose) based on molecularly imprinted polymer (MIP) modified on glassy carbon electrode was systematically investigated. It was expected to work like a solid ion selective electrode (ISE) where the specific carrier are the imprinted sites. The polymer for the selective recognition of glucose and fructose were synthesized by coelectropolymerizing the 3-hydroxyphenyl boronic acid and phenol with reducing sugar (glucose or fructose) complex. The phenol could not only provide more hydroxyl but also promote the electron transfer because of its benzene ring structure and oxygen. The principle of reducing sugars detection at the MIP modified glassy carbon electrode (MIP/GCE) was to form a covalent binding which was reversible when changing the binding conditions and had a quick response to the electrochemical potential of the fabricated sensor. The imprinted polymer films covered on the electrode surface could improve the sensitivity of the sensor response remarkably. Under the optimal experimental conditions, the potential change and the concentration of glucose and fructose were linearly related from 0.75 to 18 mM. The detection limit of glucose and fructose was 0.23 mM and 0.35 mM, respectively. In addition, we had successfully evaluated the applicability of the sensitive sensor according to detect reducing sugars in practical samples.