Disposable Sandwich-type Electrochemical Sensor for Selective Detection of Glucose Based on Boronate Affinity

A disposable sandwich-type electrochemical sensor for selective detection of glucose was established. The primary receptor, 3-aminophenylboronic acid was grafted covalently onto the surface of screen-printed carbon electrodes through an in situ-generated diazo-reaction. Glucose was first captured by boronic acid group on the electrode, followed by captureing an electroactive ferroceneboronic acid (FcBA) as the secondary receptor to form bidentate glucose-boronic complex. Electrochemical impedance spectroscopy was applied to characterize the construction of sandwich-type disposable sensor. In the sandwich assay, current response of captured FcBA on the electrode was dependent on the concentration of glucose. The sandwich assay showed higher selectivity for glucose than that for fructose, mannose, galactose and other electroactive interferences including uric acid, ascorbic acid and dopamine, and exhibited a dynamic concentration range of glucose from 0.5 to 20.0 mmol L −1 . The disposable sensor demonstrated a good reproducibility with 2.2 % relative standard deviation (RSD). In addition, the disposable glucose sensor was used in detection of the trace glucose in the clinical urine samples.