Sensitive electrochemical detection of glucose based on electrospun La0.88Sr0.12MnO3 naonofibers modified electrode

Study of the correlation between the magnetic and electrical properties of the La0.6Sr0.4MnO3 compound

In this work, we investigated the relationship between the electrical and magnetic properties of the superparamagnetic (SPM) La0.6Sr0.4MnO3 (S1C0) compound prepared by the sol-gel method. The (S1C0) sample displayed a ferromagnetic metallic (FMM) behavior at low temperatures and a paramagnetic semiconductor (PMSC) behavior at high temperatures. The FMM behavior was described by the Zener Double Exchange (ZDE) polynomial law containing the contributions of the electron-electron (e-e) interactions and the electron-magnon (e-m) scattering. The PMSC behavior was described by the Mott Variable Range Hopping (Mott-VRH) transport model. The semiconductor/metallic transition temperature has been approximated at the blocking temperature. The Thermal Coefficient of Resistivity (TCR), which exhibits a linear variation around ambient temperature, can be used as a calibration curve for thermometry. Thus, our sample can be considered as a good candidate for the detection of infrared radiation used in night vision bolometer technologies.

Sensitive Electrochemical Detection of Bioactive Molecules (Hydrogen Peroxide, Glucose, Dopamine) with Perovskites-Based Sensors

Perovskite-modified electrodes have received increasing attention in the last decade, due to their electrocatalytic properties to undergo the sensitive and selective detection of bioactive molecules, such as hydrogen peroxide, glucose, and dopamine. In this review paper, different types of perovskites involved for their electrocatalytic properties are described, and the proposed mechanism of detection is presented. The analytical performances obtained for different electroactive molecules are listed and compared with those in terms of the type of perovskite used, its nanostructuration, and its association with other conductive nanomaterials. The analytical performance obtained with perovskites is shown to be better than those of Ni and Co oxide-based electrochemical sensors. Main trends and future challenges for enlarging and improving the use of perovskite-based electrochemical sensors are then discussed.

The electrochemical applications of rare earth-based nanomaterials

This review presents a general description of the synthesis and electrochemical properties of rare earth-based nanomaterials and their electrochemical applications.

Scalable cross-point resistive switching memory and mechanism through an understanding of H2O2/glucose sensing using an IrOx/Al2O3/W structure

The resistive switching characteristics of a scalable IrO_x/Al₂O₃/W cross-point structure and its mechanism for pH/H₂O₂ sensing along with glucose detection have been investigated for the first time. Porous IrO_x and Ir³⁺/Ir⁴⁺ oxidation states are observed via high-resolution transmission electron microscope, field-emission scanning electron spectroscopy, and X-ray photo-electron spectroscopy. The 20 nm-thick IrO_x devices in sidewall contact show consecutive long dc cycles at a low current compliance (CC) of 10 μA, multi-level operation with CC varying from 10 μA to 100 μA, and long program/erase endurance of >10⁹ cycles with 100 ns pulse width. IrO_x with a thickness of 2 nm in the IrO_x/Al₂O₃/SiO₂/p-Si structure has shown super-Nernstian pH sensitivity of 115 mV per pH, and detection of H₂O₂ over the range of 1-100 nM is also achieved owing to the porous and reduction-oxidation (redox) characteristics of the IrO_x membrane, whereas a pure Al₂O₃/SiO₂ membrane does not show H₂O₂ sensing. A simulation based on Schottky, hopping, and Fowler-Nordheim tunneling conduction, and a redox reaction, is proposed. The experimental I-V curve matches very well with simulation. The resistive switching mechanism is owing to O^2- ion migration, and the redox reaction of Ir³⁺/Ir⁴⁺ at the IrO_x/Al₂O₃ interface through H₂O₂ sensing as well as Schottky barrier height modulation is responsible. Glucose at a low concentration of 10 pM is detected using a completely new process in the IrO_x/Al₂O₃/W cross-point structure. Therefore, this cross-point memory shows a method for low cost, scalable, memory with low current, multi-level operation, which will be useful for future highly dense three-dimensional (3D) memory and as a bio-sensor for the future diagnosis of human diseases.

Recent advances in electrospun metal-oxide nanofiber based interfaces for electrochemical biosensing

Synthesis of various electrospun metal-oxide nanofibers and their application towards electrochemical enzymatic and enzyme-free biosensor platforms has been critically discussed.