Lactic acid (LA) serves as a freshness marker in certain foods. In the present work, electrified interfaces of different nature (i.e.
View Article and Find Full Text PDFSensing acetylcholine has been predominantly based on enzymatic strategies using acetylcholine esterase and choline oxidase because of its electrochemical inertness. Electrified liquid-liquid interfaces are not limited to oxidation/reduction processes, and can be utilized to detect non-redox molecules which cannot be detected using conventional solid electrodes. In this study, a disposable micropipette tip based liquid-organogel interface, in the presence/absence of calixarene has been developed as a platform for sensing acetylcholine.
View Article and Find Full Text PDFInvestigating the behavior of analytes at the electrode surface is crucial in understanding the electrochemical and electrocatalytic reactions. Although Surface Enhanced Raman Scattering (SERS) is sensitive to minor chemical changes in the analyte, it is not widely used to study the reaction mechanisms on nonplasmonic surfaces because of the interference from plasmonic SERS substrates. In this study, we have investigated the redox reaction of Nile Blue A on a glassy carbon surface using pinhole-free silica-coated silver nanoparticles for Raman signal enhancement.
View Article and Find Full Text PDFPutrescine and cadaverine are biogenic amines that serve as potential biomarkers for several types of cancers and monitoring food quality. Electrochemical sensing of putrescine and cadaverine by non-enzymatic routes remains a challenge because of their inertness at unmodified electrode surfaces and hence a liquid-liquid interface strategy has been employed for their detection. In the present study, electrochemical sensing of cadaverine and putrescine has been demonstrated by simple and facilitated ion-transfer processes using a liquid-liquid microinterface supported by a microcapillary.
View Article and Find Full Text PDFThe present work reports the electrochemical sensing of acrylamide (AM) using a poly(methylene blue)-modified glassy carbon electrode (PMB/GCE) where PMB functions as an electrochemical reporter. PMB was prepared by electrochemical polymerization of methylene blue. Electrochemical sensing of AM was facilitated by the interaction between AM and PMB.
View Article and Find Full Text PDFBiogenic amines (BA) are biomolecules of low molecular weight with organic basic functionalities (amine group) that are formed by the microbial decarboxylation of amino acids of fermented food/beverages. Hence BAs are an important indicator in estimating the freshness and quality of meat, seafood, and industrial food products with high protein content. The reaction of BAs with nitrites available in certain meat products forms nitrosoamine, a carcinogenic compound.
View Article and Find Full Text PDFAn electrocatalytic sensor for hydrazine using copper sulfide-ordered mesoporous carbon (CuS-OMC) is described. A facile solvothermal synthetic strategy was adopted for CuS-OMC and the ordered mesoporous carbon was obtained through nanocasting method. The synthesized CuS-OMC was characterized using microscopic and spectrochemical techniques.
View Article and Find Full Text PDFWe describe the ultrasonic assisted preparation of barium stannate-graphitic carbon nitride nanocomposite (BSO-gCN) by a simple method and its application in electrochemical detection of 4-nitrophenol via electro-oxidation. A bath type ultrasonic cleaner with ultrasonic power and ultrasonic frequency of 100 W and 50 Hz, respectively, was used for the synthesis of BSO-gCN nanocomposite material. The prepared BSO-gCN nanocomposite was characterized by employing several spectroscopic and microscopic techniques such as X-ray diffraction, X-ray photoelectron spectroscopy, fourier transform infra-red, field emission scanning electron microscopy, and high resolution transmission electron microscopy, to unravel the structural and electronic features of the prepared nanocomposite.
View Article and Find Full Text PDFIn this paper, Co-Al layered double hydroxides (LDHs), Co-Al LDHs/poly(o-phenylenediamine) (PoPD) and Ag nanoparticles decorated Co-Al LDHs/PoPD (Ag@Co-Al LDH/PoPD) samples were prepared. The as-prepared samples were characterized by XRD, Raman, XPS, FT-IR, DRS-UV-Vis, PL and TGA techniques. The salient features of morphology and size of the samples were determined using FESEM, and HR-TEM.
View Article and Find Full Text PDFNi/NiO (nickel/nickel oxide) core-shell nanostructures were synthesized through a facile combustible redox reaction. Remarkably, the hetero-phase boundary with different crystalline orientations offered dual properties, which helped in bifunctional catalysis. Presence of a metallic Ni phase changed physicochemical properties and some emerging applications (magnetic properties, optical conductivity, electrochemical sensitivity, catalytic behaviour) could be foreseen.
View Article and Find Full Text PDFEthylene diamine-based porous organic polymer (EPOP) was synthesized, carbonized at different temperatures, and characterized. The successful formation of the triazine polymer was confirmed by Fourier-transform infrared spectroscopy, C, and N cross-polarization magic angle spinning solid-state NMR. The two-dimensional layered architecture and graphitic nature of the samples resembled that of nitrogen-doped amorphous carbon, as confirmed by Raman, powder X-ray diffraction, and transmission electron microscopy measurements.
View Article and Find Full Text PDFMinimizing the shuttle effect by constraining polysulfides to the cathode compartment and activating the passive layer between cathode and separator are highly important for improving the Li-S cell performance, Coulombic efficiency, and cycle life. Here, we report a submicron thin coating of permselective sulfonated poly(ether ether ketone) (SPEEK) composite layer on the separator that would reduce polysulfide crossover, imparting a significant improvement in cycle life. It is observed that SPEEK increases the stability, and adding Nafion improves the capacity value.
View Article and Find Full Text PDFWe illustrate a facile approach for in situ synthesis of Pd-gum arabic/reduced graphene oxide (Pd-GA/RGO) using GA as the reducing agent, which favors the instantaneous reduction of both Pd ions and GO into Pd nanoparticles (NPs) and RGO. From the morphological analysis of Pd-GA/RGO, we observed highly dispersed spherical 5nm Pd NPs decorated over RGO. The as-synthesized Pd-GA/RGO composite was employed for the catalytic reduction and the electrochemical detection of 4-nitrophenol (4-NP), respectively.
View Article and Find Full Text PDFA novel microporous three-dimensional pomegranate-like micro-scavenger cage (P-MSC) composite has been synthesized by immobilization of iron phyllosilicates clay onto a Prussian blue (PB)/alginate matrix and tested for the removal of radioactive cesium from aqueous solution. Experimental results show that the adsorption capacity increases with increasing the inactive cesium concentration from 1 ppm to 30 ppm, which may be attributed to greater number of adsorption sites and further increase in the inactive cesium concentration has no effect. The P-MSC composite exhibit maximum adsorption capacity of 108.
View Article and Find Full Text PDFSpectrochim Acta A Mol Biomol Spectrosc
March 2015
A series of acyclic Schiff base chromium(III) complexes were synthesized with the aid of microwave irradiation method. The complexes were characterized on the basis of elemental analysis, spectral analysis such as UV-Visible, Fourier transform infrared (FT-IR), nuclear magnetic resonance (NMR), electron paramagnetic resonance (EPR) spectroscopies and electrospray ionization (ESI) mass spectrometry. Electrochemical analysis of the complexes indicates the presence of chromium ion in +3 oxidation state.
View Article and Find Full Text PDFSpectrochim Acta A Mol Biomol Spectrosc
August 2014
The gold nanoparticles (AuNPs) were synthesized by using naturally available Punica Granatum fruit extract as reducing and stabilizing agent. The biosynthesized AuNPs was characterized by using UV-Vis, fluorescence, high resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD), Fourier transform infrared (FTIR) and thermogravimetric (TGA) analysis. The surface plasmon resonance (SPR) band at 585nm confirmed the reduction of auric chloride to AuNPs.
View Article and Find Full Text PDFA poly(methylene blue)-modified glassy carbon electrode (PMB/GCE) was fabricated by electropolymerisation of methylene blue on a GCE and further utilized to investigate the electrochemical determination of 4-nitrophenol (4-NP) by cyclic voltammetry (CV), differential pulse voltammetry and chronocoulometry. The morphology of the PMB on GCE was examined using a scanning electron microscope (SEM). An oxidation peak of 4-NP at the PMB modified electrode was observed at 0.
View Article and Find Full Text PDF