Improved potentiometric response of solid-contact lanthanum (III) selective electrode Original Research Article

For the first time, the analytical application of integrate ionophore-transducer material based on magnetic graphene hybrids and 2,2-dithiodipyridine (DTDP) in solid-contact lanthanum (III) selective electrode is reported. The attachment of Fe3O4 nanoparticles (NPs) to graphene oxide (GO) for magnetic graphene hybrid is achieved by covalent bonding, and the universal problem, Fe3O4 NPs may easily leach out from the graphene during application, is successfully solved by the method above. The proposed electrode exhibits an excellent near-Nernstian response to lanthanum (III) ranging from 1.0 × 10−9 to 1.0 × 10−3 M with a slope of 17.81 mV/dec. Moreover, the excellent performance on fairly good selectivity, wide applicable pH range (3.0_8.0), fast response time (10 s) and long life time (2 months) reveal the superiority of the electrode. Most importantly, we have made a great improvement in the detection limit (2.75 × 10−10 M), which brings new dawn to the real-time detection of lanthanum (III) using ion selective electrode.