Nanostructured titanium dioxide (TiO2) has a potential platform for the removal of organic contaminants, but it has some limitations. To overcome these limitations, we devised a promising strategy in the present work, the heterostructures of TiO2 sensitized by molybdenum disulfide (MoS2) nanoflowers synthesized by the mechanochemical route and utilized as an efficient photocatalyst for methyl orange (MO) degradation. The surface of TiO2 sensitized by MoS2 was comprehensively characterized by X-ray diffraction (XRD), Raman spectroscopy, Fourier transform-infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), energy dispersive spectroscopy (EDS), UV-vis diffuse reflectance spectroscopy (UV-vis DRS), photoluminescence spectroscopy (PL), Brunauer-Emmett-Teller (BET) surface area, and thermogravimetric analysis (TGA). From XRD results, the optimized MoS2-TiO2 (5.0 wt %) nanocomposite showcases the lowest crystallite size of 14.79 nm than pristine TiO2 (20 nm). The FT-IR and XPS analyses of the MoS2-TiO2 nanocomposite exhibit the strong interaction between MoS2 and TiO2. The photocatalytic results show that sensitization of TiO2 by MoS2 drastically enhanced the photocatalytic activity of pristine TiO2. According to the obtained results, the optimal amount of MoS2 loading was assumed to be 5.0 wt %, which exhibited a 21% increment of MO photodegradation efficiency compared to pristine TiO2 under UV-vis light. The outline of the overall study describes the superior photocatalytic performance of 5.0 wt % MoS2-TiO2 nanocomposite which is ascribed to the delayed recombination by efficient charge transfer, high surface area, and elevated surface oxygen vacancies. The context of the obtained results designates that the sensitization of TiO2 with MoS2 is a very efficient nanomaterial for photocatalytic applications.

Nanostructured TiO2 Sensitized with MoS2 Nanoflowers for Enhanced Photodegradation Efficiency toward Methyl Orange.

Spinel MCo2O4 (M = Ni, Fe, Mn, Cu and Zn) demonstrates excellent physicochemical properties due to the combined effects of M2+ and Co3+ cations. Their inimitable optical, electronic, and mechanical properties open up windows for a broad range of promising applications. The development of novel spinels has opened virtually infinite possibilities for the development of different sensors. The association of nanomaterials with conventional electrodes or other substrates can produce completely novel and high performance sensors. The knowledge about the nanomaterials allows us to tailor sensors for desired applications. In this regard, the spinel MCo2O4 based materials and their composites offer great promise for the design and development of high-performance electrochemical sensors to detect target species in solution or in gas phase. Aiming to shed light on these important materials, this review presents the role of such cobaltites and their composites towards the development of electrochemical sensors with improved analytical properties for sensing in solution as well as gas phase. A critical comparison of the proposed sensors using these MCo2O4-based materials with other chemically-modified sensors considered the best choices in the literature for some target molecules is presented in order to demonstrate the benefits of such materials. Further, future perspectives and opportunities in these exciting research fields are also commented based on their current progress.

Feasible strategies to promote the sensing performances of spinel MCo2O4 (M = Ni, Fe, Mn, Cu and Zn) based electrochemical sensors: a review

Currently, there is growing interest in screening and quantifying antioxidants from biological samples in the quest for natural and effective antioxidants to combat free radical-related pathological complications. Antioxidants play an important role in human health and provide a defense against many diseases. Due to the valuable dietary role of these compounds, the analysis and determination of their amount in food is of particular importance. In recent years, many attempts have been made to provide simple, fast, and economical analytical approaches for the on-site detection and determination of antioxidant activity in food antioxidants. In this regard, electrochemical sensors and biosensors are considered promising tools for antioxidant research due to their high sensitivity, fast response time, and ease of miniaturization; thus, they are used in a variety of fields, including food analysis, drug screening, and toxicity research. Herein, we review the recent advances in sensors and biosensors for the detection of antioxidants, underlying principles, and emphasizing advantages, along with limitations regarding the ability to discriminate between the specific antioxidant or quantifying total antioxidant content. In this work, both direct and indirect methods for antioxidants detecting with electrochemical sensors and biosensors are analyzed in detail. This review aims to prove how electrochemical sensors and biosensors represent reliable alternatives to conventional methods for antioxidant analysis.

/pdf/a-review-on-electrochemical-sensors-and-biosensors-used-in-3vqqcfxn.pdf

A Review on Electrochemical Sensors and Biosensors Used in Assessing Antioxidant Activity

Massive engineering of spinel cobalt tin oxide/tin oxide-based electrocatalyst for the selective voltammetric determination of antibiotic drug furaltadone in water samples

Electrochemical sensor-based barium zirconate on sulphur-doped graphitic carbon nitride for the simultaneous determination of nitrofurantoin (antibacterial agent) and nilutamide (anticancer drug)

Transition metal-doped metal oxides with a typical spinal structure are considered to be the most promising electrodes for superior electrochemical sensors because of their better electrochemical conductivity and electron transfer properties than those of individual metal oxides. Here, we demonstrated the simple preparation of spinel-type zinc cobaltate nanosheets through the polyol method for the electrochemical determination of nitrofurantoin. Various spectroscopic techniques were used to characterize the as-synthesized material, and electrochemical impedance spectroscopy, cyclic voltammetry, and differential pulse voltammetry techniques were used to study the electrochemical properties. The electrochemical detection of nitrofurantoin was performed based on the fabricated electrode, generating outstanding electrocatalytic performance with a limit of detection of 0.013 μM and excellent sensitivity of 2.866 μA μM−1. Moreover, the modified electrode exhibits excellent selectivity and good recoveries in real sample analysis towards the detection of nitrofurantoin.

Highly sensitive electrode materials for the voltammetric determination of nitrofurantoin based on zinc cobaltate nanosheets

Simple sonochemical synthesis of flake-ball shaped bismuth vanadate for voltammetric detection of furazolidone

Simple chemical synthesis is highly efficient to develop metal oxide composites as active electrode materials for an electrochemical sensor displaying enhanced catalytic sites, fast kinetics, and easy accessibility to target molecules. In this work, a cobalt oxide/tin oxide (Co3O4/SnO2) composite was prepared by a facile co-precipitation method and employed for the voltammetric determination of ornidazole (ODZ). The structural and morphological properties of the as-synthesized materials were studied through XRD, FT-IR, BET, FE-SEM, TEM, and XPS analyses. The electrochemical activity was investigated using cyclic voltammetric (CV) and linear sweep voltammetric (LSV) techniques. The electrochemical signal shows that the modified glassy carbon electrode (Co3O4/SnO2/GCE) revealed superior sensing ability in rapid ODZ detection compared to a single component of Co3O4 or SnO2. The performance was investigated over a wide linear range of 0.2 to 1185.8 μM with a low detection limit of 0.059 μM for ODZ, respectively, at a low-cost Co3O4/SnO2 modified electrode. Good selectivity was observed in the presence of NFT, 2-NA, and Cd2+ by the ODZ sensor. Furthermore, the excellent stability, repeatability, and reproducibility suggest that the constructed electrode based on Co3O4/SnO2/GCE is promising for real-time application in water samples.

Development of an electrochemical sensor based on a cobalt oxide/tin oxide composite for determination of antibiotic drug ornidazole

Preparation of three dimensional flower-like cobalt phosphate as dual functional electrocatalyst for flavonoids sensing and supercapacitor applications

http://www.electrochemsci.org/papers/vol15/150807390.pdf

Chelliah Koventhan

Papers

Highly sensitive electrode materials for the voltammetric determination of nitrofurantoin based on zinc cobaltate nanosheets

Simple sonochemical synthesis of flake-ball shaped bismuth vanadate for voltammetric detection of furazolidone

Development of an electrochemical sensor based on a cobalt oxide/tin oxide composite for determination of antibiotic drug ornidazole

Preparation of three dimensional flower-like cobalt phosphate as dual functional electrocatalyst for flavonoids sensing and supercapacitor applications

Efficient Hydrothermal Synthesis of Flake-Like Molybdenum Disulfide for Selective Electrochemical Detection of Metol in Water Real Samples