All-solid-state Nitrate-selective Electrodes Based on Graphene Aerogels

YAN Yuting;MAO Hanping;WANG Kun;ZUO Zhiqiang;School of Agricultural Equipment Engineering,Jiangsu University;

all-solid-state ion-selective electrode;;graphene aerogels;;potentiometric sensor;;nitrate detection

It is of great advantage for advanced potentiometric detection systems to develop ion-selective electrodes( ISEs) by using solid-state transducer materials. Conducting polymers are the most used solidstate transducing materials. However,their reliability is strongly related to their chemical stability and the formation of internal water films. The ISEs with the implementation of graphene as ion-to-electron transducer were reported. And it was found that the electric current for the graphene modified electrode was decreased with the decrease of thickness of the graphene transducing layer. Thus,a novel all-solidstate nitrate-selective electrode with implementation of 3D multilayer graphene aerogels( GAs) as solidcontact layer was developed. And the as-prepared GAs was characterized by transmission electron microscopy( TEM). The GAs films as transducer materials in potentiometric all-solid-state ISEs showed better electrochemical performance in reducing graphene oxide( RGO) films due to its multilayer structure,which was demonstrated by the cyclic voltammetry( CV). As a proof of concept, the performance of the newly developed electrode was evaluated on the basis of nitrate ions. And the hydrophobic nature of the GAs film was characterized via the potentiometric water layer test. The obtained results showed that graphene can significantly facilitate the ion-to-electron transducer and prevent the formation of water layer between the ion-selective membrane and the graphene layer. And the new nitrateselective electrode displayed a low detection limit of 10~(-4. 2)mol/L. GAs offered great promise as a reliable high-performance transducer material for solid-state ISE sensors. Furthermore,the developed electrode exhibited fast response and excellent potential stability,which made it very promising for routine analysis and application.