All Solid State Graphene Based Potentiometric Sensors forMonitoring of Mercury Ions inWasteWater Samples

Document Type: Original Research Paper

Authors

1 Center of Excellence in Electrochemistry,Faculty of Chemistry,University of Tehran,Tehran, Iran

2 Departments of Occupational Health, School of Public Health, and Institute for Environmental Research, Tehran University of Medical Sciences, Tehran, Iran

Abstract

In this work, all-solid-state potentiometric PVC membrane sensor was introduced for fast and
simple monitoring of mercury ions in waste water samples. The all solid sate electrode is made based on a
conductive composite of graphite, reduced graphene oxide, epoxy resin on a copper wire. A thin layer PVC
membrane is then coated on the surface of the new conducting transducer. PVC membrane is composed of 30%
PVC, 62% NPOE as plasticizer, 3% ionic liquid, and 5% Hg2+ ion imprinted polymer (IIP). The sensing element
of the sensor is an artificial host which is imprinted by vinyl pyridine and a suitable cross-linker. The sensor
shows a Nernstian response of 29.4±0.3 mV/decade. Dynamic linear range of the sensor is 1.0×10-8-1.0×10-3
mol/L of the mercury concentration and detection limit of 3.2×10-9 mol/L. The interference of different ionic
species with the response of the electrode shows a good selectivity of the proposed sensor. The proposed sensor
is successfully applied in determination of mercury ions in some waste water samples.

Keywords