An integrated all-solid-state screen-printed potentiometric sensor based on a three-dimensional self-assembled graphene aerogel

Abstract

An integrated all-solid-state screen-printed ion-selective potentiometric sensor for the determination of Cu2+ is proposed. The whole-cell potentiometric sensor incorporates a polymeric membrane copper ion-selective electrode (Cu2+-ISE) as an indicator electrode and an Ag/AgCl reference electrode with a polyvinyl butyral reference membrane. The three-dimensional (3D) self-assembled porous graphene aerogel (PGA) can be conveniently and rapidly electrodeposited on the electrode substrate surface. Due to its interior 3D interconnected porous structures, the PGA has a large electrical double layer capacitance and fast charge transfer capability, which make it promising to be used as solid contact for the fabrication of the Cu2+-ISE. The developed potentiometric sensor shows a good Nernstian response over a range from 10−6 to 10−3 M with a detection limit of 10−6.5 M. In addition, the sensor exhibits a stable potential response with the absence of an undesirable water layer at the ion-selective membrane/PGA interface.