Graphene Oxide Bulk-Modified Screen-Printed Electrodes Provide Beneficial Electroanalytical Sensing Capabilities

Abstract

We demonstrate a facile methodology for the mass production of graphene oxide (GO) bulk-modified screen-printed electrodes (GO-SPEs) that are economical, highly reproducible and provide analytically useful outputs. Through fabricating GO-SPEs with varying percentage mass incorporations (2.5%, 5%, 7.5% and 10%) of GO, an electrocatalytic effect towards the chosen electroanalytical probes is observed, which increases with greater GO incorporated compared to bare/graphite SPEs. The optimum mass ratio of 10% GO to 90% carbon ink produces an electroanalytical signal towards dopamine (DA) and uric acid (UA) which is ca. ×10 greater in magnitude than that achievable at a bare/unmodified graphite SPE. Furthermore, 10% GO-SPEs exhibit a competitively low limit of detection (3σ) towards DA at ca. 81 nM, which is superior to that of a bare/unmodified graphite SPE at ca. 780 nM. The improved analytical response is attributed to the large number of oxygenated species inhabiting the edge and defect sites of the GO nanosheets, which are able to exhibit electrocatalytic responses towards inner-sphere electrochemical analytes. Our reported methodology is simple, scalable, and cost effective for the fabrication of GO-SPEs that display highly competitive LODs and are of significant interest for use in commercial and medicinal applications.

Electrochemical Properties of Screen-Printed Carbon Nano-Onion Electrodes

“…The analytical sensitivity (slope of the calibration curve) is approximately 4 times higher for the CNO/GRT SPE compared to the commercial GRT SPE for dopamine. This improved performance may be associated with the oxygenated species on the electrode surface due to the incorporation of the CNO particles in the ink formulation, which facilitates electrocatalytic reactions [ 59 ].…”

Electroanalytical overview: The electroanalytical detection of theophylline

“…Related to graphene is of course graphene oxide. This is an often overlooked material [52][53][54] which can give rise to beneficial responses to target analytes and itself is a useful nanomaterial in electrochemistry due to its rich oxygenated surface. Shetti and co-workers [55] utilised graphene oxide with nanoclays to realise a paste electrode for the sensing of theophylline with improved results observed using this electrode configuration over that of carbon paste electrode.…”

Disposable and Flexible Electrochemical Paper‐based Analytical Devices Using Low‐cost Conductive Ink

“…Carbon-based materials such as graphite, carbon black, carbon nanotubes, or graphene are commonly applied for ePAD construction using a variety of techniques, e. g., as inkjet printing [3], pencil drawing [2], stencil printing [11], sputtering [3], or even can be obtained directly on paper by pyrolysis using laser [14]. Carbon materials are extremely versatile compounds and have been successfully applied in the construction of screen-printed carbon electrodes (SPCE) owing to their interesting physicochemical properties such as high chem-ical stability, good conductivity, low-cost, broad potential windows, and unique chemical surface structures [15][16][17] Due to these properties, inks containing these compounds are particularly attractive for fast and scalable ePAD construction for sensing applications [18]. Despite the availability of commercial carbon inks, there are a limited number of manufactures, especially in developing countries.…”