Exploring the origins of the apparent “electrocatalytic” oxidation of kojic acid at graphene modified electrodes

Abstract

We explore the recent reports that the use of graphene modified electrodes gives rise to the electrocatalytic oxidation of kojic acid. It is demonstrated that large quantifiable voltammetric signatures are observed on bare/unmodified graphitic electrodes, which are shown to be analytically useful and superior to those observed at graphene modified alternatives. This work is of importance as it shows that control experiments are critical and must be undertaken before "electrocatalysis" is conferred when investigating graphene in electrochemistry. In terms of the electroanalytical response of graphene modified electrodes, a bare edge plane pyrolytic graphite electrode is shown to give rise to an improved linear range and limit of detection, questioning the need to modify electrodes with graphene.

Electrochemically Reduced Graphene Oxide for Forensic Electrochemistry: Detection of Cocaine and its Adulterants Paracetamol, Caffeine and Levamisole

“…The surface modification with ERGO enables the screening of all species, which would not be reached using the bare GCE, so ERGO modification confers better selectivity and additional sensitivity. Although the k 0 for the unmodified GCE was higher than the value obtained for the ERGO‐modified GCE, the improved response obtained on the modified surface seems to be related to oxygenated groups and defects presented on the ERGO structure, similarly to results presented in the literature . In this context, the proposed procedure using ERGO‐modified GCE becomes an alternative for a quick and inexpensive assay (in terms of equipment and reagents) in relation to the conventional analytical methods most used for the control of forensic samples.…”

Imparting improvements in electrochemical sensors: evaluation of different carbon blacks that give rise to significant improvement in the performance of electroanalytical sensing platforms

“…393.0 mV) when compared with the others electrodes (ca. 485.1 mV for EPPG and 500.2 mV GCE), after was carried out successive additions of AP into a 0.1 mol L −1 phosphate buffer solution, pH 7.0. , however it is most remarkable the VXC72RCB-CTS/GCE exhibits an improvement over that of EPPG in terms of the observed sensitivity (slope of the calibration plot); usually EPPG shows the best sensitivity among different carbonaceous materials as can found in the literature [6,52,53]. The linear equations for the electroanalytical response using VXC72RCB-CTS/GCE are as follows: j (µAcm DA concentrations have been associated with neurological disorders; thus, the determination of the DA concentration can be very important in diagnostic applications [7,54].…”

“…In the last decade, plenty of carbonaceous materials, such as, carbon nanofibers [1], carbon nanotube [2][3][4][5], graphene [6,7], carbon black [8,9], fulerenes [10,11], carbon nanoparticles [12,13] and carbonaceous foam materials [14] have been studied and used to develop new sensors and biosensors. Carbon black is generally used as inexpensive and high effectiveness reinforcement for rubber tyres and others polymer-matrix composites [15,16] with its characteristics allowing carbon black to develop a fibrous morphology which exhibits a reinforcing ability.…”

Why is the electroanalytical performance of carbon paste electrodes involving an ionic liquid binder higher than paraffinic binders? A simulation investigation

“…60,61 The state of highly coordinated ion pairs obviously belongs to a highly stable state consistent with the maximum possible long range electrostatic interactions between ions. Consequently, the improved electrochemical properties and performance observed are due to an increment in the available edge plane.…”