electrophoretic deposition of graphene oxide on screen-imprinted carbon electrode and its modified using tl3+-imprinted polymer as ionophere for determination of thallium (iii) ions by potentiometric sensor

Abstract: a heavy and metallic element in the environment is thallium. the most dangerous features of thallium are damage to testicular tissue, liver, peripheral nerves, kidney intestine, hair loss, and even it's suspected for a human carcinogen. thallium is present in nature as tl (i) and tl (iii) ions, and each thallium oxidation state has its bioavailability and toxicity property. universally, the concentration of thallium in the aqueous solution is very low, so the analytical methods are required to determine it in the environment [1]. in the electrochemical methods, the construction of effective electrode is principle challenge. the success of an electrochemical method depending on the successful choice of electrodes. recently, screen-printed electrode (spe) was applied for determining metal ions. this electrodes have been miniaturize and low cost [2]. the spe surface was modified with different materials such as nanoparticles and surfactant for enhance the electrochemical performance. graphene oxide is an important nanoparticle among the new nanoparticles. go has suitable properties such as conductivity and great surface area. a screen-printed carbon electrode system for the determination of thallium (iii) was introduced using screen-printing technology. an electrophoretic deposition (epd) method has been used for the deposition graphen oxide nanosheets onto the surface of spe. this research study to determining thallium (iii) ions have described a novel ion-selective electrode according to thallium (iii)-imprinted polymer particles dispersed in 2-nitrophenyloctyl ether (npoe) and embedded in a polyvinylchloride (pvc) matrix. the tl (iii)-ion selective electrode showed a nernstian response for thallium (iii) ions over the dynamic concentration range of 0.49 to 20.5 μm, with a slope of 19.6 mv per decade. the response time was determined to be about 20 seconds. one of the significant points is the selectivity coefficient of the prepared ion-selective electrode. the selectivity of this electrode for other ions is less than 1.1× 10-3 and this indicates the selectivity of the electrode to thallium (iii) ions and other ions are less disturbing.the desired electrode showed good selectivity over a wide range of ions. the accuracy of the suggested electrode was investigated in spiked tap water.