posted on 2021-12-02, 16:13authored byMatthew
J. Whittingham, Nicholas J. Hurst, Robert D. Crapnell, Alejandro Garcia-Miranda Ferrari, Elias Blanco, Trevor J. Davies, Craig E. Banks
Screen-printed electrodes (SPEs)
are ubiquitous within the field
of electrochemistry and are commonplace within the arsenal of electrochemists.
Their popularity stems from their reproducibility, versatility, and
extremely low-cost production, allowing their utilization as single-shot
electrodes and thus removing the need for tedious electrode pretreatments.
Many SPE studies have explored changing the working electrode composition
and/or size to benefit the researcher’s specific applications.
In this paper, we explore a critical parameter of SPEs that is often
overlooked; namely, we explore changing the length of the SPE connections.
We provide evidence of resistance changes through altering the connection
length to the working electrode through theoretical calculations,
multimeter measurements, and electrochemical impedance spectroscopy
(EIS). We demonstrate that changing the physical length of SPE connections
gives rise to more accurate heterogeneous electrode kinetics, which
cannot be overcome simply through IR compensation. Significant improvements
are observed when utilized as the basis of electrochemical sensing
platforms for sodium nitrite, β-nicotinamide adenine dinucleotide
(NADH), and lead (II). This work has a significant impact upon the
field of SPEs and highlights the need for researchers to characterize
and define their specific electrode performance. Without such fundamental
characterization as the length and resistance of the SPE used, direct
comparisons between two different systems for similar applications
are obsolete. We therefore suggest that, when using SPEs in the future,
experimentalists report the length of the working electrode connection
alongside the measured resistance (multimeter or EIS) to facilitate
this standardization across the field.