Abstract: The present invention relates to a new device for selective arsenic sensing using electrochemically reduced graphene oxide (ERGO) based reusable flexible electrode strip. Active electrode of the device was prepared by a very simple method in which the thin film of graphene oxide (GO) was reduced electrochemically at a low DC potential (0 to -1.5 V). The said device selectively detects As3+ in field water sample within a wide range of concentrations with a limit of detection of less than 25 ppb. More importantly, the selectivity of the electrode is independent of conductivity and TDS levels of measured field water samples which were collected from various parts of India. Selective detection of As3+ by ERGO was controlled by optimizing the surface electronic conductivity through structural modification of it during electroreduction process.

Abstract: Reduced graphene oxide@polystyrene (RGO—PS) composite was synthesized using reduced graphene oxide (RGO), styrene monomer and divinylbenzene through an in-situ polymerization process. The RGO—PS composite was functionalized with sulfonate and quaternary amine functionalities for making positive and negative integrated electro-adsorbent-ion exchange resins (EAIERs), respectively. These EAIERs ‘molecular constructs’ were used as CDI electrodes and desalination was performed for the removal of different ions. A high electro-adsorption capacity of ˜15.93 mg/g for Cl? using 802 ?S NaCl solution was observed in laboratory batch experiments which was much higher than the adsorption capacity of RGO electrodes reported earlier (˜2-3 mg/g).