Journal article
All-solid-state potassium-selective electrode using graphene as the solid contact
Graphene sheets are used for the first time to fabricate a new type of solid-contact ion-selective electrode (SC-ISE) as the intermediate layer between an ionophore-doped solvent polymeric membrane and a glassy carbon electrode. The new transducing layer was characterized by transmission electron microscopy, scanning electron microscopy, cyclic voltammetry and electrochemical impedance spectroscopy.
The performance of the new K+−selective electrodes was examined by a potentiometric water layer test, potentiometric measurements, and current reversal chronopotentiometry. The obtained potentiometric sensors were characterized with a calibration line of slope close to Nernstian (59.2 mV/decade) within the activity from 10−4.5 to 0.1 M.
The high capacitance of the graphene solid contacts results in a signal that is stable over one week. The short response time is less than 10 s for activities higher than 10−5 M. The potential drift of the electrodes was calculated from the slope of the curves at longer times (ΔE/Δt = 1.2 × 10−5 V s−1 (I = 1 nA) and ΔE/Δt = 5.5 × 10−5 V s−1 (I = 5 nA)).
All the results indicate that graphene is a promising material for use as a transducer layer for SC-ISEs.
Language: | English |
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Publisher: | The Royal Society of Chemistry |
Year: | 2012 |
Pages: | 618-623 |
ISSN: | 13645528 and 00032654 |
Types: | Journal article |
DOI: | 10.1039/c1an15705a |
ORCIDs: | Gan, Shiyu |