All-solid-state potassium-selective electrode using graphene as the solid contactThis article is part of a web theme in Analyst and Analytical Methods on Future Electroanalytical Developments, highlighting important developments and novel applications. Also in this theme is work presented at the Eirelec 2011 meeting, dedicated to Professor Malcolm Smyth on the occasion of his 60th birthday.Electronic supplementary information (ESI) available: TEM and SEM images of the graphene and transducer lay

• Main Authors: Li, Fenghua, Ye, Junjin, Zhou, Min, Gan, Shiyu, Zhang, Qixian, Han, Dongxue, Niu, Li
• Format: Journal Article
• Language: English
• Published: 10.01.2012
• ISSN: 0003-2654; 1364-5528
• DOI: 10.1039/c1an15705a

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 ( E / t = 1.2 10 5 V s 1 ( I = 1 nA) and E / t = 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. Graphene sheets are used for the first time to fabricate a solid-contact ion-selective electrode (SC-ISE) as the intermediate layer.