A. Elangovan

Green synthesized gold nanoparticles decorated graphene oxide for sensitive determination of chloramphenicol in milk, powdered milk, honey and eye drops.

A simple and rapid green synthesis using Bischofia javanica Blume leaves as reducing agent was developed for the preparation of gold nanoparticles (AuNPs). AuNPs decorated graphene oxide (AuNPs/GO) was prepared and employed for the sensitive amperometric determination of chloramphenicol. The green biosynthesis requires less than 40s to reduce gold salts to AuNPs. The formations of AuNPs and AuNPs/GO were evaluated by scanning electron and atomic force microscopies, UV-Visible and energy dispersive X-ray spectroscopies, X-ray diffraction studies, and electrochemical methods. AuNPs/GO composite film modified electrode was fabricated and shown excellent electrocatalytic ability towards chloramphenicol. Under optimal conditions, the amperometric sensing platform has delivered wide linear range of 1.5-2.95μM, low detection limit of 0.25μM and high sensitivity of 3.81μAμM(-1)cm(-2). The developed sensor exhibited good repeatability and reproducibility, anti-interference ability and long-term storage stability. Practical feasibility of the sensor has been demonstrated in food samples (milk, powdered milk and honey) and pharmaceutical sample (eye drops). The green synthesized AuNPs/GO composite has great potential for analysis of food samples in food safety measures.

A highly sensitive and selective electrochemical determination of non-steroidal prostate anti-cancer drug nilutamide based on f-MWCNT in tablet and human blood serum sample

A novel electrochemical sensor based on the functionalized multiwalled carbon nanotube (f-MWCNT) was successfully developed for the sensitive and selective determination of non-steroidal prostate anti-cancer drug nilutamide in tablet and blood serum samples. The f-MWCNT was prepared by the simple reflux method and characterized by the scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), Raman spectroscopy, X-ray powder diffraction (XRD) and fourier transform infrared spectroscopy (FT-IR). Interestingly, the f-MWCNT was exhibited a superior electrocatalytic activity towards the anti-cancer drug nilutamide when compared with pristine MWCNT and unmodified electrodes. Besides, the electrochemical sensor was revealed an excellent current response for the determination of nilutamide with wide linear ranges (0.01-21μM and 28-535μM), high sensitivity (11.023 and 1.412μA μM-1cm2) and very low detection limit (LOD) 0.2nM. The developed electrochemical sensor was showed an excellent selectivity even in the presence of electrochemically active biological substances and nitro aromatic compounds. Moreover, it manifested a good reproducibility and stability. In addition, the f-MWCNT modified glassy carbon electrode (GCE) sensor was successfully applied for the detection of nilutamide in tablet and blood serum sample.

Phyto mediated biogenic synthesis of gold nanoparticles using Cerasus serrulata and its utility in detecting hydrazine, microbial activity and DFT studies

Green synthesis of Au-NPs using Cerasus serrulata (C. serrulata) leaves extract has emerged as a nontoxic and ecofriendly option, as compared to currently available chemical and/or physical methods and also Au-NPs act as both reducing and stabilizing agent. The developed Au-NPs were characterized with XRD, UV-visible spectroscopy, FTIR, SEM, TEM and chemical constituents of C. serrulata leaves extract after and before reduction of Au-NPs have been identified through GC-MS. TEM images confirmed that biosynthesized Au-NPs were spherical in shape and approximately in the range of 5-25 nm. The electrochemical results showed remarkable electrocatalytic activity of the Au-NPs-modified GC electrode in the detection of environmentally hazardous pollutant like hydrazine. The modified electrode exhibits a wide linear range 5 nM to 272 μM with low detection limit 0.05 μM. The fabricated sensor shows good selectivity towards other electroactive species as well. Thus the proposed sensor seems to be a potential candidate for developing a simple, rapid and cost-effective electrochemical sensor. The synthesized Au-NPs exhibited higher antibacterial activity against gram negative (Escherichia coli) than gram positive (Staphylococcus aureus) bacteria. DFT studies revealed that the coumarin (CM) present in the C. serrulata leaves extract demonstrated greater reducing and stabilizing properties compared to the properties of other compounds like butylhydroxytoluene (BHT) and hydrocoumarin (HCM) present in the extract.

Sonochemical Synthesis of Sulfur Doped Reduced Graphene Oxide Supported CuS Nanoparticles for the Non-Enzymatic Glucose Sensor Applications

Over the present material synthesis routes, the sonochemical route is highly efficient and comfortable way to produce nanostructured materials. In this way, the copper sulfide (CuS-covellite) and sulfur doped reduced graphene oxide (S-rGO) nanocomposite was prepared by sonochemical method. Interestingly, the structure of the as-prepared S-rGO/CuS was changed from the covellite to digenite phase. Herein, the S-rGO was act as a mild oxidizer and liable for the structural transformations. These structural changes are sequentially studied by various physicochemical characterizations such as Fourier transform infrared spectroscopy (FT-IR), Raman spectroscopy, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and Transmission electron microscopy (TEM). After scrupulous structural evaluations, the transformation of CuS phase was identified and documented. This oxidized CuS has an excellent electrocatalytic activity when compare to the bulk CuS. This S-rGO/CuS was further used for the determination of glucose and acquired good electrocatalytic performances. This S-rGO/CuS was exhibited a wide linear concentration range, 0.0001–3.88 mM and 3.88–20.17 mM, and a low-level detection limit of 32 nM. Moreover, we have validated the practicability of our developed glucose sensor in real biological samples.

Green synthesis of a novel flower-like cerium vanadate microstructure for electrochemical detection of tryptophan in food and biological samples

In this present investigation, we introduced a novel electrochemical sensor for the detection of tryptophan (TRP) based on green pompoms flower-like cerium vanadate (CeVO4). The flower-like CeVO4 microstructure was prepared by the simple hydrothermal treatment with the assistance of urea for the first time. The as-prepared flower-like CeVO4 microstructure was characterized by various analytical and spectroscopic techniques such as X-ray diffraction, Raman spectroscopy fourier transform infrared spectroscopy, scanning electron microscopy and energy-dispersive X-ray spectroscopy studies. The electrochemical properties are evaluated by the cyclic voltammetry (CV) and differential pulse voltammetry (DPV). As an electrochemical sensor, the green pompoms flower-like CeVO4 modified glassy carbon electrode (GCE) displayed an excellent electrocatalytic activity for the detection of TRP. The obtained electrochemical results revealed that the oxidation of TRP, exhibited a lower potential and higher anodic peak current when compared to unmodified GCE. These results were suggested that the flower-like CeVO4/GCE have a good electrocatalytic activity towards the TRP oxidation. The flower-like CeVO4 sensor exhibited the wide linear concentration range and low detection limit of 0.1-94µM and 0.024µM respectively. Finally, the proposed sensor was successfully applied to the determination of TRP in real sample analysis such as food and biological samples with satisfied recoveries.

A facile graphene oxide based sensor for electrochemical detection of prostate anti-cancer (anti-testosterone) drug flutamide in biological samples

A novel electrochemical sensor based on graphene oxide (GO) modified glassy carbon electrode (GCE) has been successfully developed for the determination of anti-cancer drug flutamide for the first time. The morphology and structure of the prepared GO were characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), UV-visible spectroscopy, scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), field emission-scanning electron microscopy (FE-SEM), and transmission electron microscopy (TEM). The electrochemical properties of the GO were studied by electrochemical impedance spectroscopy (EIS). GO modified GCE was fabricated and utilized to study the electrochemical performance of flutamide by cyclic voltammetry (CV) and linear sweep voltammetry (LSV). As an electrochemical sensor, GO modified GCE exhibited strong electrocatalytic activity towards the reduction of flutamide. Interestingly, the electrochemical sensor displayed an excellent current response for the detection of flutamide with wide linear response range, excellent limit of detection and good sensitivity of 0.009 to 1.9 μM, 6 nM and 29.55 μA μM−1 cm−2, respectively. The proposed sensor has good repeatability, reproducibility, stability and selectivity even in the presence of biologically co-interfering substances. GO modified GCE sensor was successfully used for the detection of flutamide (spiked) in various blood serum samples.

One-step sonochemical synthesis of 1D β-stannous tungstate nanorods: An efficient and excellent electrocatalyst for the selective electrochemical detection of antipsychotic drug chlorpromazine

In the modern world, the contamination of ecosystem by human and veterinary pharmaceutical drugs through the metabolic excretion, improper disposal/industrial waste has been subjected to a hot issue. Therefore, exploitation of exclusive structured material and reliable technique is a necessary task to the precise detection of drugs. With this regards, we made an effort for the fabrication of novel one-dimensional (1D) stannous tungstate nanorods (β-SnW NRs) via simple sonochemical approach and used as an electrochemical sensor for the detection of antipsychotic drug chlorpromazine (CPZ) for the first time. The crystallographic structure, surface topology, elemental compositions and their distributions and ionic states were enquired by different spectroscopic techniques such as XRD, FTIR, SEM, EDS, elemental mapping and XPS analysis. The developed β-SnW NRs/GCE sensor exhibits a rapid and sensitive electrochemical response towards CPZ sensing with wide linear response range (0.01-457 µM), high sensitivity (2.487 µA µM-1 cm-2), low detection limit (0.003 µM) and excellent selectivity. Besides, the as-proposed electrochemical sensor was successfully applied to real sample analysis in commercial CPZ drug and biological fluids and the acquired recovery results are quite satisfactory. The proposed sonochemical method for the preparation of β-SnW NRs is low cost, very simple, fast and efficient for sensor applications.

Biosynthesis of silver nanoparticles by using Camellia japonica leaf extract for the electrocatalytic reduction of nitrobenzene and photocatalytic degradation of Eosin-Y

In the present study, sphere-like silver nanoparticles (Ag-NPs) were synthesized by using Camellia japonica leaf extract and its remediation industrial pollutants such as nitrobenzene and Eosin-Y (EY). As-prepared sphere-like Ag-NPs were characterized by various analytical and spectroscopic methods such as UV-visible spectroscopy, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), High-resolution transmission electron microscopy (HR-TEM), Energy dispersive X-ray spectra (EDX), and the chemical constituents of the leaf extract were also analyzed by using Gas chromatography and Mass Spectroscopy (GC-MS). Fascinatingly, the as-prepared sphere-like Ag-NPs exhibits excellent electrocatalytic and photocatalytic activity for the reduction of nitrobenzene and photo-degradation of EY dye respectively. The Cyclic voltammetry (CV) and amperometric (i-t) studies realized that the electrochemical behavior of sphere-like Ag-NPs modified electrode on nitrobenzene reduction. The proposed nitrobenzene sensor exhibited appreciable wide linear response range and low detection limit of 0.05-21μM, 23-2593μM and 12nM, respectively. The Ag-NPs modified electrode showed excellent selectivity towards the nitrobenzene detection even in the presence of common metal ions and nitroaromatic containing substances. On the other hand, Ag-NPs have excellent photocatalytic activity with >97% degradation of EY dye after irradiated 60min. These results indicated that the growth of sphere-like Ag-NPs should be a proficient.

Adsorption and corrosion inhibiting behavior of a new S-triazine derivative

AbstarctThe inhibiting effect of 4, 6-bis (5-mercapto-1, 3, 4-thiadiazol-amine)2-phenylamino-1,3,5-triazine BMTDT on the corrosion of mild steel in acidic media has been investigated by weight loss and electrochemical methods. Results obtained reveal that this organic compound is a very good inhibitor. BMTDT is able to reduce the corrosion of steel more effectively in 1M HCl than in 1 M H2SO4. The effect of polarization studies show that the adsorption of BMTDT follows physical adsorption in both acids without changing the mechanism of the hydrogen evolution reaction. Surface analyses were also carried out to establish the mechanism of corrosion inhibition of mild steel in acidic media. The adsorption of this inhibitor on the mild steel surface in obeys the Langmuir absorption isotherm in 1 M HCl and Frumkin adsorption isotherm in 1M H2SO4. The corrosion behavior of mild steel with addition of different concentration of BMTDT was studied in the temperature range 308–333 K. The associated activation parameters and adsorption free energies have been determined and discussed.

Crystal structure of bis­(4-acetyl­anilinium) tetra­chlorido­cobaltate(II)

The structure of the title salt, (C8H10NO)2[CoCl4], is isotypic with the analogous cuprate(II) structure. The asymmetric unit contains one 4-acetylanilinium cation and one half of a tetrachloridocobaltate(II) anion for which the CoII atom and two Cl− ligands lie on a mirror plane. The Co—Cl distances in the distorted tetrahedral anion range from 2.2519 (6) to 2.2954 (9) Å and the Cl—Co—Cl angles range from 106.53 (2) to 110.81 (4)°. In the crystal, cations are self-assembled by intermolecular N—H⋯O hydrogen-bonding interactions, leading to a C(8) chain motif with the chains running parallel to the b axis. π–π stacking interactions between benzene rings, with a centroid-to-centroid distance of 3.709 Å, are also observed along this direction. The CoCl4 2− anions are sandwiched between the cationic chains and interact with each other through intermolecular N—H⋯Cl hydrogen-bonding interactions, forming a three-dimensional network structure.