The electrochemical performance of graphene modified electrodes: An analytical perspective

Abstract

We explore the use of graphene modified electrodes towards the electroanalytical sensing of various analytes, namely dopamine hydrochloride, uric acid, acetaminophen and p-benzoquinone via cyclic voltammetry. In line with literature methodologies and to investigate the full-implications of employing graphene in this electrochemical context, we modify electrode substrates that exhibit either fast or slow electron transfer kinetics (edge- or basal- plane pyrolytic graphite electrodes respectively) with well characterised commercially available graphene that has not been chemically treated, is free from surfactants and as a result of its fabrication has an extremely low oxygen content, allowing the true electroanalytical applicability of graphene to be properly de-convoluted and determined. In comparison to the unmodified underlying electrode substrates (constructed from graphite), we find that graphene exhibits a reduced analytical performance in terms of sensitivity, linearity and observed detection limits towards each of the various analytes studied within. Owing to graphene's structural composition, low proportion of edge plane sites and consequent slow heterogeneous electron transfer rates, there appears to be no advantages, for the analytes studied here, of employing graphene in this electroanalytical context.

Simultaneous determination of uric acid and dopamine using a carbon fiber electrode modified by layer-by-layer assembly of graphene and gold nanoparticles

“…6a depicts the linear relationship between the oxidation peak currents and DA concentration in the range of 0.59-43.955 μM. The corresponding linear regression equation is defined as I pa = 37.4099+0.5996C DA (R=0.992), and the lower detection limit for DA is observed to be 0.59 μM (S/N=3), which is lower than previously reported results [27][28][29]. Meanwhile, a similar experiment was conducted with UA in the presence of 8 μM DA.…”

“…As shown in the inset of Fig. 6b, the linear relationship between the oxidation peak currents of UA and the UA concentration is defined as I pa =24.262+0.1001C UA (R=0.997) in the range of 12.6-413.62 μM and the lower detection limit is observed to be 12.6 μM (S/N=3), which is lower than what was previously reported [28,29]. The above results show that GE/Au/GE/CFE is well response for the determination of DA and UA.…”

Insights into electrocatalytic activity of epitaxial graphene on SiC from cyclic voltammetry and ac impedance spectroscopy

“…Due to rather poor electrocatalytic activity of intrinsic graphene and graphite [25][26][27], the electrodes were activated by anodization [28,29]. It has been shown that during electrochemical oxidation, several functional groups connect to the graphite basal plane and many multivacancies and small etch pits appear [30].…”

An Oxygen Reduction Study of Graphene-Based Nanomaterials of Different Origin

“…This feature is in good agreement with the specification data of graphene nanopowder and graphene nanoplatelet aggregates given by Graphene Supermarket and Strem Chemicals, respectively. Based on the literature, the low O/C ratio refers to the near true nature of graphene [53]. The main difference between GO and rGO is that GO is with higher oxygen content than rGO [54,55].…”