03100nas a2200193 4500008004100000022001400041245014400055210006900199260011000268300001600378490000600394520226300400100002402663700002302687700002002710700002402730700002402754856012802778 2015 eng d a2040-336400aNanocrystalline Fe-Fe2O3 particle-deposited N-doped graphene as an activity-modulated Pt-free electrocatalyst for oxygen reduction reaction0 aNanocrystalline FeFe2O3 particledeposited Ndoped graphene as an  aTHOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLANDbROYAL SOC CHEMISTRYcOCT a20117-201250 v73 a

The size-controlled growth of nanocrystalline Fe-Fe2O3 particles (2-3 nm) and their concomitant dispersion on N-doped graphene (Fe-Fe2O3/NGr) could be attained when the mutually assisted redox reaction between NGr and Fe3+ ions could be controlled within the aqueous droplets of a water-in-oil emulsion. The synergistic interaction existing between Fe-Fe2O3 and NGr helped the system to narrow down the overpotential for the oxygen reduction reaction (ORR) by bringing a significant positive shift to the reduction onset potential, which is just 15 mV higher than its Pt-counterpart. In addition, the half-wave potential (E-1/2) of Fe-Fe2O3/NGr is found to be improved by a considerable amount of 135 mV in comparison to the system formed by dispersing Fe-Fe2O3 nanoparticles on reduced graphene oxide (Fe-Fe2O3/RGO), which indicates the presence of a higher number of active sites in Fe-Fe2O3/NGr. Despite this, the ORR kinetics of Fe-Fe2O3/NGr are found to be shifted significantly to the preferred 4-electron-transfer pathway compared to NGr and Fe-Fe2O3/RGO. Consequently, the H2O2% was found to be reduced by 78.3% for Fe-Fe2O3/NGr (13.0%) in comparison to Fe-Fe2O3/RGO (51.2%) and NGr (41.0%) at -0.30 V (vs. Hg/HgO). This difference in the yield of H2O2 formed between the systems along with the improvements observed in terms of the oxygen reduction onset and E-1/2 in the case of Fe-Fe2O3/NGr reveals the activity modulation achieved for the latter is due to the coexistence of factors such as the presence of the mixed valancies of iron nanoparticles, small size and homogeneous distribution of Fe-Fe2O3 nanoparticles and the electronic modifications induced by the doped nitrogen in NGr. A controlled interplay of these factors looks like worked favorably in the case of Fe-Fe2O3/NGr. As a realistic system level validation, Fe-Fe2O3/NGr was employed as the cathode electrode of a single cell in a solid alkaline electrolyte membrane fuel cell (AEMFC). The system could display an open circuit voltage (OCV) of 0.73 V and maximum power and current densities of 54.40 mW cm(-2) and 200 mA cm(-2), respectively, which are comparable to the performance characteristics of a similar system derived by using 40 wt% Pt/C as the cathode electrode.

1 aDhavale, Vishal, M.1 aSingh, Santosh, K.1 aNadeema, Ayasha1 aGaikwad, Sachin, S.1 aKurungot, Sreekumar uhttp://library.ncl.res.in/content/nanocrystalline-fe-fe2o3-particle-deposited-n-doped-graphene-activity-modulated-pt-free-000720nas a2200181 4500008004100000022001500041245014300056210006900199260000800268300001600276490000600292100002400298700002300322700002000345700002400365700002400389856012500413 2017 eng d a 2040-336400aNanocrystalline Fe-Fe2O3 particledeposited N-doped graphene as an activity-modulated Pt-free electrocatalyst for oxygen reduction reaction0 aNanocrystalline FeFe2O3 particledeposited Ndoped graphene as an  cSEP a13341-133420 v91 aDhavale, Vishal, M.1 aSingh, Santosh, K.1 aNadeema, Ayasha1 aGaikwad, Sachin, S.1 aKurungot, Sreekumar uhttp://library.ncl.res.in/content/nanocrystalline-fe-fe2o3-particledeposited-n-doped-graphene-activity-modulated-pt-free02822nas a2200313 4500008004100000022001400041245009900055210006900154260000800223300001600231490000700247520186600254653001702120653001302137653001802150653001402168653003202182653001302214653001602227653001202243653001302255653001102268100002202279700002302301700001902324700002102343700001502364856012902379 2017 eng d a1463-907600aNature of selenium hydrogen bonding: gas phase spectroscopy and quantum chemistry calculations0 aNature of selenium hydrogen bonding gas phase spectroscopy and q cSEP a24179-241870 v193 a

Subsequent to the recent re-definition of hydrogen bonding by the IUPAC committee, there has been a growing search for finding the presence of this ever interesting non-covalent interaction between a hydrogen atom in an X-H group and any other atom in the periodic table. In recent gas phase experiments, it has been observed that hydrogen bonding interactions involving S and Se are of similar strength to those with an O atom. However, there is no clear explanation for the unusual strength of this interaction in the case of hydrogen bond acceptors which are not conventional electronegative atoms. In this work, we have explored the nature of Se hydrogen bonding by studying indole...dimethyl selenide (indmse) and phenol...dimethyl selenide (phdmse) complexes using gas phase IR spectroscopy and quantum chemistry calculations. We have found through various energy decomposition analysis (EDA) methods and natural bond orbital (NBO) calculations that, along with electrostatics and polarization, charge transfer interactions are important to understand Se/S hydrogen bonding and there is a delicate balance between the various interactions that plays the crucial role rather than a single component of the interaction energy. An in-depth understanding of this type of non-covalent interaction has immense significance in biology as amino acids containing S and Se are widely present in proteins and hence hydrogen bonding interactions involving S and Se atoms contribute to the folding of proteins.

 

10aCenter-Dot-O10aClusters10aCo-Ordination10aComplexes10aintermolecular interactions10aProteins10aReplacement10aspectra10aStrength10aSulfur1 aMishra, Kamal, K.1 aSingh, Santosh, K.1 aGhosh, Paulami1 aGhosh, Debashree1 aDas, Aloke uhttp://library.ncl.res.in/content/nature-selenium-hydrogen-bonding-gas-phase-spectroscopy-and-quantum-chemistry-calculations02138nas a2200217 4500008004100000245014400041210006900185260000800254300001300262490000800275520132900283100002201612700001701634700002901651700001801680700002301698700002401721700002301745700002201768856013001790 2018 eng d00aNucleic aptamer modified porous reduced graphene oxide/MoS2 based electrodes for viral detection: application to human papillomavirus (HPV)0 aNucleic aptamer modified porous reduced graphene oxideMoS2 based cJUN a991-10000 v2623 aNext to graphene nanomaterials, molybdenum disulfide (MoS2) offers large surface area that can enhance its biosensing performance. In this work, we investigate the performance of glassy carbon (GC) electrodes modified successively with porous reduced graphene oxide (prGO) and molybdenum sulfide (MoS2) for the sensitive and selective detection of the L1-major capsid protein of human papilloma virus (HPV). Owing to the difficulties to perform serological assays and HPV culture efficiently, tools based on molecular recognition are becoming of great importance. We developed here an electrochemical sensor for HPV upon covalent functionalization of the electrode with an aptamer Sc5-c3, a RNA aptamer targeted against the HPV-16 L1 protein. Using differential pulse voltammetry (DPV) and an optimized sensor interface, a linear relationship between the peak current density of a redox couple such as [Fe(CN)6]4- and the concentration of HPV-16 L1 proteins in the range of 0.2-2 ng mL(-1) (3.5 pM-35.3 pM) could be reached with a detection limit of 0.1 ng mL(-1) (1.75 pM). Cross-reactivity studies demonstrated high selectivity over potential interfering species such as HPV-16 E6, opening new opportunities of the developed concept for the development of point of care devices. (C) 2018 Elsevier B.V. All rights reserved.1 aChekin, Fereshteh1 aBagga, Komal1 aSubramanian, Palaniappan1 aJijie, Roxana1 aSingh, Santosh, K.1 aKurungot, Sreekumar1 aBoukherroub, Rabah1 aSzunerits, Sabine uhttp://library.ncl.res.in/content/nucleic-aptamer-modified-porous-reduced-graphene-oxidemos2-based-electrodes-viral-detection01899nas a2200181 4500008004100000022001400041245012300055210006900178260000900247300001400256490000600270520122500276100002101501700002001522700002301542700002401565856012801589 2020 eng d a2516-023000aNiFe layered double hydroxide-decorated N-doped entangled-graphene framework: a robust water oxidation electrocatalyst0 aNiFe layered double hydroxidedecorated Ndoped entangledgraphene  cAPR  a1709-17170 v23 a

Three dimensional (3D) porous carbon materials are highly desirable for electrochemical applications owing to their high surface area and porosity. Uniformly distributed porosity in the 3D architecture of carbon support materials allows reactant molecules to access more electrochemically active centres and simultaneously facilitate removal of the product formed during electrochemical reactions. Herein, we have prepared a nitrogen-doped entangled graphene framework (NEGF), decorated with NiFe-LDH nanostructures by an in situ solvothermal method followed by freeze-drying at high vacuum pressure and low temperature. The freeze-drying method helped to prevent the restacking of the graphene sheets and the formation of a high surface area nitrogen-doped entangled graphene framework (NEGF) supported NiFe-LDHs. The incorporation of the NEGF has significantly reduced the overpotential for the electrochemical oxygen evolution reaction (OER) in 1 M KOH solution. This corresponds to an overpotential reduction from 340 mV for NiFe-LDHs to 290 mV for NiFe-LDH/NEGF to reach the benchmark current density of 10 mA cm(-2). The preparation of the catalyst is conceived through a low-temperature scalable process.

1 aManna, Narugopal1 aAyasha, Nadeema1 aSingh, Santosh, K.1 aKurungot, Sreekumar uhttp://library.ncl.res.in/content/nife-layered-double-hydroxide-decorated-n-doped-entangled-graphene-framework-robust-water