Iridium Oxide Enabled Sensors Applications

There have been numerous studies applying iridium oxides in different applications to explore their proton-change-based reactions since the 1980s. Iridium oxide can be fabricated directly by applying electrodeposition, sputter-coating method, or oxidation of iridium wire. Generally, there have been currently two approaches in applying iridium oxide to enable its sensing applications. One was to improve or create different electrolytes with (non-)electrodeposition method for better performance of Nernst Constant with the temperature-related system. The mechanism behind the scenes were summarized herein. The other was to change the structure of iridium oxide through different kinds of templates such as photolithography patterns, or template-assisted direct growth methods, etc. to improve the sensing performance. The detection targets varied widely from intracellular cell pH, glucose in an artificial sample or actual urine sample, and the hydrogen peroxide, glutamate or organophosphate pesticides, metal-ions, etc. This review paper has focused on the mechanism of electrodeposition of iridium oxide in aqueous conditions and the sensing applications towards different biomolecules compounds. Finally, we summarize future trends on Iridium oxide based sensing and predict future work that could be further explored.

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Recent advances in understanding oxygen evolution reaction mechanisms over iridium oxide

Inorganic Chemistry Frontiers ◽

10.1039/d0qi01465f ◽

2021 ◽

Author(s):

Takahiro Naito ◽

Tatsuya Shinagawa ◽

Takeshi Nishimoto ◽

Kazuhiro Takanabe

Keyword(s):

Reaction Mechanism ◽

Oxygen Evolution ◽

Oxygen Evolution Reaction ◽

Reaction Mechanisms ◽

State Of The Art ◽

Iridium Oxide ◽

The State ◽

Computational Studies ◽

Recent Advances ◽

Iridium Oxides

Recent spectroscopic and computational studies concerning the oxygen evolution reaction over iridium oxides are reviewed to provide the state-of-the-art understanding of its reaction mechanism.

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Mode Sensitivity Exploration of Silica–Titania Waveguide for Refractive Index Sensing Applications

Sensors ◽

10.3390/s21227452 ◽

2021 ◽

Vol 21 (22) ◽

pp. 7452

Author(s):

Muhammad A. Butt ◽

Andrzej Kaźmierczak ◽

Cuma Tyszkiewicz ◽

Paweł Karasiński ◽

Ryszard Piramidowicz

Keyword(s):

Refractive Index ◽

High Performance ◽

Near Infrared ◽

Sol Gel ◽

Cost Effective ◽

Dip Coating ◽

Infrared Wavelength ◽

Refractive Index Sensing ◽

Sensing Applications ◽

Coating Method

In this paper, a novel and cost-effective photonic platform based on silica–titania material is discussed. The silica–titania thin films were grown utilizing the sol–gel dip-coating method and characterized with the help of the prism-insertion technique. Afterwards, the mode sensitivity analysis of the silica–titania ridge waveguide is investigated via the finite element method. Silica–titania waveguide systems are highly attractive due to their ease of development, low fabrication cost, low propagation losses and operation in both visible and near-infrared wavelength ranges. Finally, a ring resonator (RR) sensor device was modelled for refractive index sensing applications, offering a sensitivity of 230 nm/RIU, a figure of merit (FOM) of 418.2 RIU−1, and Q-factor of 2247.5 at the improved geometric parameters. We believe that the abovementioned integrated photonics platform is highly suitable for high-performance and economically reasonable optical sensing devices.

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Yttrium Doped TiO2 Thin Film for Gas Sensing Application Prepared by Spin Coating Method

10.21203/rs.3.rs-106302/v1 ◽

2020 ◽

Author(s):

M Abdul Kaiyum ◽

Naim Ahmed ◽

Arif Alam ◽

M Shamimur Rahman

Keyword(s):

Thin Film ◽

Photoelectron Spectroscopy ◽

Gas Sensing ◽

Low Cost ◽

Pure Titanium ◽

X Ray ◽

Sensing Applications ◽

Coating Method ◽

Set Up ◽

Spin Coater

Abstract Yttrium (Y) doped and pure Titanium Di-oxide (TiO2) thin films were prepared by using spin coater. The coater was set up in laboratory with low cost investment. The films were calcined at 450 °C for 1 hour. For characterization, Scanning Electron Microscopy (SEM), Energy Dispersive X-Ray Analysis (EDX), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Atomic Force Microscopy (AFM) were carried out. LCR Bridge - GW Instek LCR-821 was used for gas sensing applications. XPS showed that the change of electronic structure due to Y doping. SEM and AFM analysis were carried out to determine the surface morphology of the films. Yttrium (Y) decreased the crystallite size of the films and increased the surface roughness and porosity value, which was very good for many sensing applications. Gas sensing property of the deposited films were improved by the incorporation of yttrium impurities and the sensing property improved almost two times than pure TiO2 thin film. Different researches have been done their research related to this topic but no one researchers provide a precise explanation of their results, authors of this research have tried to do that. Moreover the films were prepared by a simple spin coater to reduce the production cost also.

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SnO2 Nano/Microfibers for Gas Sensors

Defect and Diffusion Forum ◽

10.4028/www.scientific.net/ddf.405.324 ◽

2020 ◽

Vol 405 ◽

pp. 324-329

Author(s):

Erika Mudra ◽

Ivan Shepa ◽

Alexandra Kovalcikova ◽

Ondrej Milkovič ◽

Jan Dusza

Keyword(s):

Gas Sensors ◽

Gas Sensing ◽

Operating Temperature ◽

Band Gap Energy ◽

Calcination Process ◽

Sensing Applications ◽

Amorphous Nature ◽

Coating Method ◽

Type Semiconductor

SnO2 is an n-type semiconductor with the band gap energy of 3.6 eV. It has been widely studied for gas sensing applications, the sensitivity of which can be easily tuned by the operating temperature. The presented paper is focused on the preparation and detailed characterization of the hollow SnO2 nano/microfibers suitable for gas detection sensors. Ceramic SnO2 fibers were produced by needleless electrospinning and followed by the calcination process. The characterization was performed by SEM, TEM, XRD, and Raman spectroscopy. The precursor PVP/SnO2 fibers had amorphous nature. The calcination of the electro spun precursor resulted in the formation of hollow crystalline fibrous structures. The formation mechanism of hollow fibers has been described. Subsequently, a homogeneous fibrous layer was created by the spin coating method for gas sensing applications.

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The electronic structure of iridium oxide electrodes active in water splitting

Physical Chemistry Chemical Physics ◽

10.1039/c5cp06997a ◽

2016 ◽

Vol 18 (4) ◽

pp. 2292-2296 ◽

Cited By ~ 157

Author(s):

V. Pfeifer ◽

T. E. Jones ◽

J. J. Velasco Vélez ◽

C. Massué ◽

M. T. Greiner ◽

...

Keyword(s):

Electronic Structure ◽

Water Splitting ◽

Iridium Oxide ◽

Oxygen Species ◽

Oxide Electrodes ◽

Iridium Oxides

Combining XPS, NEXAFS, and DFT reveals anionic and cationic defects in OER-active iridium oxides give rise to electrophilic oxygen species.

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Nanohoop Rotaxanes via Active Template Syntheses and Their Potential in Sensing Applications

10.26434/chemrxiv.7634612 ◽

2019 ◽

Author(s):

Jeff Van Raden ◽

Brittany White ◽

Lev N. Zakharov ◽

Ramesh Jasti

Keyword(s):

Metal Binding ◽

Fluorescence Response ◽

Design And Synthesis ◽

Sensing Applications ◽

Bright Fluorescence ◽

New Type ◽

Aqueous Conditions ◽

Mechanical Bonds

<p>The synthesis of nanohoop rotaxanes via two different active template strategies is reported. By preparing triazole-embedded rotaxanes, the observation of metal binding events in both organic and aqueous conditions are readily observed via dramatic changes in nanohoop emission. Inspired by this result, we then describe the design and synthesis of a new type of "self-destructing" nanohoop rotaxane that, in the presence of an analyte, releases a quenched nanohoop macrocycle resulting in a bright fluorescence response. More broadly, this work highlights the conceptual advantages of combining compact π-rich macrocyclic frameworks with mechanical bonds formed via active-template syntheses. </p><p></p>

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A Comparative Analysis of Iridium Oxide Nanowires in Electrical Detection of Biochemical Reactions

MRS Proceedings ◽

10.1557/proc-1095-ee08-22 ◽

2008 ◽

Vol 1095 ◽

Author(s):

Vinu Venkatraman ◽

Ravikiran Reddy ◽

Fengyan Zhang ◽

David Evans ◽

Sheng-Teng Hsu ◽

...

Keyword(s):

Performance Metrics ◽

Physical Adsorption ◽

Chemical Properties ◽

Precious Metals ◽

High Sensitivity ◽

Iridium Oxide ◽

Biomolecular Sensing ◽

Reactive Protein ◽

Sensing Applications ◽

Inflammatory Protein

AbstractPt, Ir, Au and few other precious metals have highly conducive electrical and chemical properties; hence have been widely used in pH sensors and bimolecular sensing applications. The chief objective of this research is to highlight and demonstrate the advantages that Iridium Oxide (IrOx) nanowires offer over these competing metals in improving the performance metrics of biomolecular sensing. Iridium oxide has very good conductivity and very high charge storing capacity, and hence has an ability to detect very small changes in the surface charge. Nanowires have an ideal morphology to crowd protein molecules and highly increase the surface area of interaction. Higher area of interaction along with iridium oxide's high intrinsic physical adsorption rate, strongly enhance the rate of immobilization of biomolecules and hence enabling high sensitivity detection. Inflammatory protein, C-Reactive protein (CRP) that is a biomarker for cardiovascular disease was used as the model biomolecule for this study.

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Characterization of MWCNT-PEDOT: PSS Nanocomposite Flexible Thin Film for Piezoresistive Strain Sensing Application

Advances in Polymer Technology ◽

10.1155/2019/9320976 ◽

2019 ◽

Vol 2019 ◽

pp. 1-9

Author(s):

Roopa Hegde ◽

Koona Ramji ◽

Swapna Peravali ◽

Yallappa Shiralgi ◽

Gurumurthy Hegde ◽

...

Keyword(s):

Thin Film ◽

Gauge Factor ◽

Strain Sensing ◽

High Concentration ◽

Multiwalled Carbon ◽

Polymer Substrates ◽

Sensing Applications ◽

Coating Method ◽

Incremental Strain

Multiwalled carbon nanotubes (MWCNTs) were synthesized by the reduction of ethyl alcohol with sodium borohydride (NaBH4) under a strong basic solvent with the high concentration of sodium hydroxide (NaOH). Nanocomposites of different concentration of MWCNT dispersed in poly(3,4-ethylene dioxythiophene) polymerized with poly(4-styrene sulfonate) (PEDOT:PSS) were prepared and deposited on a flexible polyethylene terephthalate (PET) polymer substrates by the spin coating method. The thin films were characterized for their nanostructure and subsequently evaluated for their piezoresistive response. The films were subjected to an incremental strain from 0 to 6% at speed of 0.2 mm/min. The nanocomposite thin film with 0.1 wt% of MWCNT exhibits the highest gauge factor of 22.8 at 6% strain as well as the highest conductivity of 13.5 S/m. Hence, the fabricated thin film was found to be suitable for piezoresistive flexible strain sensing applications.

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CVD transfer-free graphene for sensing applications

Beilstein Journal of Nanotechnology ◽

10.3762/bjnano.8.102 ◽

2017 ◽

Vol 8 ◽

pp. 1015-1022 ◽

Cited By ~ 5

Author(s):

Chiara Schiattarella ◽

Sten Vollebregt ◽

Tiziana Polichetti ◽

Brigida Alfano ◽

Ettore Massera ◽

...

Keyword(s):

Chemical Vapour ◽

Hazardous Substances ◽

Multilayer Graphene ◽

Mo Catalyst ◽

Sensing Applications ◽

Sensing Material ◽

Free Graphene ◽

Direct Growth ◽

Different Shapes ◽

Growth Approach

The sp2 carbon-based allotropes have been extensively exploited for the realization of gas sensors in the recent years because of their high conductivity and large specific surface area. A study on graphene that was synthetized by means of a novel transfer-free fabrication approach and is employed as sensing material is herein presented. Multilayer graphene was deposited by chemical vapour deposition (CVD) mediated by CMOS-compatible Mo. The utilized technique takes advantage of the absence of damage or contamination of the synthesized graphene, because there is no need for the transfer onto a substrate. Moreover, a proper pre-patterning of the Mo catalyst allows one to obtain graphene films with different shapes and dimensions. The sensing properties of the material have been investigated by exposing the devices to NO2, NH3 and CO, which have been selected because they are well-known hazardous substances. The concentration ranges have been chosen according to the conventional monitoring of these gases. The measurements have been carried out in humid N2 environment, setting the flow rate at 500 sccm, the temperature at 25 °C and the relative humidity (RH) at 50%. An increase of the conductance response has been recorded upon exposure towards NO2, whereas a decrease of the signal has been detected towards NH3. The material appears totally insensitive towards CO. Finally, the sensing selectivity has been proven by evaluating and comparing the degree of adsorption and the interaction energies for NO2 and NH3 on graphene. The direct-growth approach for the synthesis of graphene opens a promising path towards diverse applicative scenarios, including the straightforward integration in electronic devices.

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