Fabrication of electrochemical interface based on boronic acid-modified pyrroloquinoline quinine/reduced graphene oxide composites for voltammetric determination of glycated hemoglobin

A voltammetric sensor for determination of glycated hemoglobin (HbA(1c)) was developed based on the composites of phenylboronic acid-modified pyrroloquinoline quinine (PBA-PQQ) and reduced graphene oxide. After the electrodeposition of reduced graphene oxide (ERGO) on the glassy carbon (GC) electrode, PQQ multilayer was decorated on the surface of the ERGO/GC electrode via potential cycling. Further modification with PBA would lead to the formation of the working electrode, namely PBA-PQQ/ERGO/GC electrode. PQQ on the electrode exhibited a quasi-reversible electrode process with 2-electron transfer and 2-proton participation, and the electron transfer efficiency was further enhanced by the introduction of ERGO layer. The complexation of PBA with HbA(1c) through specific boronic acid-diol recognition could cause the change of the oxidation peak current of PQQ on the electrode, which was utilized for HbA(1c) detection. Under the optimized conditions, the PBA-PQQ/ERGO/GC electrode provided high selectivity and high sensitivity for HbA(1c), detection with a linear range of 9.4-65.8 mu g mL(-1) and a low detection limit of 1.25 mu g mL(-1). The fabricated sensor was also successfully applied to determine the percentages of HbA(1c) in whole blood of healthy individuals. 2014 Published by Elsevier B.V.