A glassy carbon electrode modified with carbon nano-fragments and bismuth oxide for electrochemical analysis of trace catechol in the presence of high concentrations of hydroquinone

A glassy carbon electrode was modified with carbon nanofragments and bismuth oxide, and the resulting electrode (CNF-Bi/GCE) was applied to the voltammetric determination of catechol (CC) in the presence of a large excess (>100-fold) of hydroquinone (HQ). The CNF-Bi was synthesized by anchoring bismuth oxide on CNFs in a hydrothermal and calcining process. Compared to CNF-modified GCE and bare GCE, the CNF-Bi/GCE exhibits enhanced electrocatalytic activity with respect to the redox reaction of CC (at 0.28 V vs. SCE) and HQ (at 0.15 V). Differential pulse voltammetry was applied to quantify traces of CC in the presence of excess HQ. The calibration plot is linear in the 3 to 20 μmol L −1 concentration range, with a 0.2 μmol L −1 detection limit (at a signal-to-noise ratio of 3). These results indicate the CNF-Bi/GCE is a promising sensor for analyzing trace isomers of dihydroxybenzene. In addition, it is also applicable to the determination of ascorbic acid, dopamine, resorcin, and rutin. A glassy carbon electrode was modified with carbon nano-fragments and bismuth oxide (CNF-Bi/GCE). It was applied to the determination of trace levels of catechol (CC) in the presence of an up to >100 fold excess of hydroquinone (HQ).