Development of the New Fluoride Ion-Selective Electrode Modified with FexOy Nanoparticles

Abstract

A new modified ion-selective electrode with membranes of LaF3 single crystals with different internal contacts (solid steel or electrolyte) and with FexOy nanoparticles as loading was developed. The best response characteristic with linear potential change was found in the fluoride concentration range from 10−1 to 3.98 × 10−7 M. The detection limit for the electrolyte contact was determined at 7.41 × 10−8 M with a regression coefficient of 0.9932, while the regression coefficient for the solid contact was 0.9969. The potential change per concentration decade ranged from 50.3 to 62.4 mV, depending on whether the contact was solid or electrolytic. The prepared modified electrode has a long lifetime, as well as the possibility of application in different positions (solid contact), and it can also be used for the determination of iron ions. The electrode characterization was performed with scanning electron microscopy and elemental analysis with the technique of electron-dispersive X-ray spectroscopy.

The New Ion-Selective Electrodes Developed for Ferric Cations Determination, Modified with Synthesized Al and Fe−Based Nanoparticles

“…Merck, KGaA, Darmstadt, Germany), while pH value 5 with acetic buffer prepared by mixing sodium acetate (CH 3 COONa, p.a., Kemika, Zagreb, Croatia) and acetic acid (CH 3 COOH, p.a., VWR chemicals, Radnor, PA, USA). As it was reported before, membranes with FePO 4 , Ag 2 S, and PTFE composition showed the best response at pH = 1 [ 40 ], and ferric selective electrodes modified with nanoparticles of iron oxides showed the best response at pH = 5 [ 20 ]. The tests were carried out at RT.…”

“…Moreover, these NPs are easy to produce and offer a wide range of biomedical applications, especially hematite and magnetite [ 1 , 6 ]. The iron oxide NPs are used as sensor modifiers for the determination of various analytes, such as hydrogen peroxide [ 17 ], glucose [ 18 ], Pb, Zn, Cd [ 19 ], Cl [ 13 ], F [ 20 ], nitrites [ 21 ] and some organic compounds [ 22 , 23 , 24 ]. The technology of iron oxide NPs synthesis has been highly developed and brought to a level where it is possible to obtain the desired phase and size of NPs by defining the synthesis process [ 25 ].…”

Beyond Nonactin: Potentiometric Ammonium Ion Sensing Based on Ion-selective Membrane-free Prussian Blue Analogue Transducers

“…Regarding the ion recognition by organic ionophores through coordination interaction (Figure b), crystal ion selectivity has been known for a long time through solid ion conductors. − For example, the classic single crystal film electrode of LaF 3 can recognize the F – due to crystal size sieving and F – transport in the lattices. − However, the LaF 3 could only be used in traditional liquid-junction ISEs because it is only an ionic conductor but not an electronic conductor, which could not transform ion concentration to the electron signal. Prussian blue analogues (PBAs) are a sort of representative redox and ion intercalation materials that have been focused in battery fields − because they are characteristic of both electronic and ionic conductor (Figure c).…”

A Novel Reduced Graphene Oxide Modified Carbon Paste Electrode for Potentiometric Determination of Trihexyphenidyl Hydrochloride in Pharmaceutical and Biological Matrices

“…In the literature, there is only one work on the determination of THP using a carbon paste electrode [ 5 ]. Since nanomaterials are playing an increasingly important role in the fabrication of chemo- and bio-sensors [ 24 , 31 , 47 , 48 , 49 , 50 ] due to the possibility of their direct and easy incorporation into ion-selective membranes, synthesized reduced graphene oxide (rGO) was used in this work. A sensor for the determination of THP containing any type of nanomaterials has not yet been developed according to the available literature.…”