Electroanalytical properties of screen printed shallow recessed electrodes

Abstract

We report the fabrication of novel carbon based screen printed disc-shaped recessed electrodes (250 mm radius) which are electrochemically characterised and contrasted to other screen printed sensors previously reported upon within the literature. In these circumstances, the electrode is fabricated entirely through screen printing and the electrode geometry is defined by the dielectric (inert polymer) producing shallow recessed electrodes. In comparison to co-planar carbon screen printed electrodes, the shallow recessed screen printed electrodes exhibit a greater current density over the former. The potential electroanalytical applications of these carbon based disc-shaped shallow recessed electrodes are explored through the sensing of NADH and nitrite exhibiting analytically relevant limits of detection (3s) of 5.2 and 7.28 mM respectively. Additionally, the electroanalytical sensing of nitrite is further trialled in a canal water sample demonstrating the robust nature of the sensors analytical performance. Furthermore we explore the potential improvement of the shallow recessed electrodes through the fabrication of pentagon-shaped carbon based shallow recessed electrodes, which are compared and contrasted with shallow recessed disc electrodes towards the electroanalytical sensing of manganese(II); we believe this to be the first example of such an electrode geometry. In comparison of the observed current density the disc-shaped shallow recessed electrode offers greater sensitivity over co-planar screen printed electrode, whilst in addition to this, a pentagon-shaped recessed electrode offers improved sensitivity over even that of the disc-shaped shallow recessed screen printed electrode. The ultra-low nM sensing of manganese(II) is shown to be possible at both the disc and pentagon shallow recessed electrodes exhibiting limits of detection (3s) found to correspond to 63 and 36 nM respectively. Both the disc and pentagon-shaped shallow recessed screen printed electrodes are determined to offer greater analytical sensitivity as determined within this study and in comparison with previous literature using graphitic electrodes. The fabrication methodology of the shallow recessed electrodes is shown to be generic in nature such that the underlying carbon layer, which defines the composition of the shallow recessed working electrode, can be replaced with electrocatalytic surfaces. We demonstrate this with the fabrication of platinum disc-shaped shallow recessed screen printed electrodes, which are electrochemically characterised and explored towards the sensing of hydrazine and hydrogen peroxide displaying limits of detection (3s) of 26.3 and 44.3 mM respectively, which are found to be analytically useful.

Exploring the electrical wiring of screen-printed configurations utilised in electroanalysis

“…This electrochemical probe receives considerable attention owing to its very important role as a cofactor in many naturally occurring enzymatic reactions, and mainly because of the potential application in over 300 NAD + /NADH À dependent dehydrogenase-based biosensors [21][22][23][24][25][26][27] and consequently its electrochemical characteristics are hugely important. The kinetic parameter, 4 is tabulated as a function of peak-to-peak separation (DE P ) at a set temperature (298 K) for a one-step, one electron process.…”

“…For example, Metters et al 6 have shown the constant diverse use of screen-printed sensors to many electrochemical targets, including chromium, 7 hydrazine 6 and atropine, 8 to name a few. Many researchers have expressed the need for miniaturisation of electrochemical setups and for the continuation of electroanalytical studies.…”

Ultraflexible Screen‐Printed Graphitic Electroanalytical Sensing Platforms

“…We have previously reported on the design, fabrication and implementation of various screen‐printed electrode configurations exploring novel working electrode materials 6–9 and geometries 10–12. One such example includes the fabrication of platinum 7 and gold 6 screen‐printed sensors which were applied towards the electroanalytical sensing of chromium species (VI and III) in the case of the gold sensor, and both hydrazine and hydrogen peroxide for the case of the platinum sensor. Crucially, it was determined that the requirement for electrode potential cycling prior to utilisation (as is the case for bulk noble metal macro electrodes in order to form an oxide upon the electrode surface) was alleviated in the case of the screen‐printed sensors owing to the noble metal utilised within the screen‐printing process being in the form of an oxide.…”

Forensic electrochemistry: simultaneous voltammetric detection of MDMA and its fatal counterpart “Dr Death” (PMA)

“…This screen-printed electrode design has been previously reported. 26,28,29,33,[40][41][42][43][44] For the case of each fabricated electrode, rst a carbon ink formulation (Product Code: C2000802P2; Gwent Electronic Materials Ltd, UK), which is utilized for the efficient connection of all three electrodes and as the electrode material for both the…”