| 1. |
- Abbas, Malik Waseem, et al.
(author)
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Carbon quantum dot coated Fe3O4 hybrid composites for sensitive electrochemical detection of uric acid
- 2019
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In: Microchemical journal (Print). - : ELSEVIER SCIENCE BV. - 0026-265X .- 1095-9149. ; 146, s. 517-524
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Journal article (peer-reviewed)abstract
- The study explores carbon quantum dots (C-dots) as potential candidates for enhancing the signal sensitivity of an electrochemical sensor devised for biologically important molecule, such as uric acid (UA). The C-dots were evaluated for their electrochemical characteristics in combination with Fe3O4 nanoparticles (Fe3O4 NPs), which were applied as the primary electro-catalytic promoter. The hybrid nanocomposite (C-dots/Fe3O4 HCs) formation was achieved by facilitating the adsorption of C-dots over Fe3O4 NPs using amine-carbonyl interactions. Unlike, one pot method, the proposed strategy enables aggregation-free coverage of Fe3O4 NPs with highly conductive layer of C-dots that can act as conduction centres to support ultra-fast electron transfer kinetics to satisfy the need of high signal sensitivity. The hybrid composite demonstrated remarkable signal improvement when tested against the electrochemical oxidation of UA. The heighten current response and lower over-potential values enabled development of a DC-amperometric (DC-AMP) sensor for UA with a linear working range of 0.01 to 0.145 mu M and signal sensitivity measurable up to 6.0 x 10(-9) M. The said improvement was manifested as a synergetic outcome of active redox couple (Fe (III/II)), larger surface area of Fe3O4 NPs engulfed with a layer of highly conductive C-dots acting as efficient charge sensitisers.
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| 2. |
- Bac, Selin, et al.
(author)
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Exceptionally active and stable catalysts for CO2 reforming of glycerol to syngas
- 2019
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In: Applied Catalysis B: Environmental. - : Elsevier BV. - 0926-3373 .- 1873-3883. ; 256
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Journal article (peer-reviewed)abstract
- CO2 reforming of glycerol to syngas was studied on Al2O3-ZrO2-TiO2 (AZT) supported Rh, Ni and Co catalysts within 600–750 °C and a molar inlet CO2/glycerol ratio (CO2/G) of 1–4. Glycerol and CO2 conversions decreased in the following order: Rh/AZT > Ni/AZT > Co/AZT. Reactant conversions on Rh/AZT exceeded 90% of their thermodynamic counterparts at 750 °C and CO2/G = 2–4 at which the activity of Ni/AZT was boosted to ˜95% of the thermodynamic CO2 conversion upon increasing the residence time. The loss in CO2 conversions was below 13% during the 72 h longevity tests confirming the exceptional stability of Rh/AZT and Ni/AZT. However, Co/AZT suffered from sintering, carbon deposition and oxidation of Co sites, demonstrated via TEM-EDX, XPS, XANES and in-situ FTIR experiments. Characterization of Rh/AZT revealed no significant signs of deactivation. Ni/AZT preserved most of its original metallic pattern and gasified carbonaceous deposits during earlier stages of the reaction.
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| 3. |
- Soomro, Razium Ali, et al.
(author)
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In-situ growth of NiWO4 saw-blade-like nanostructures and their application in photo-electrochemical (PEC) immunosensor system designed for the detection of neuron-specific enolase
- 2019
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In: Biosensors & bioelectronics. - : ELSEVIER ADVANCED TECHNOLOGY. - 0956-5663 .- 1873-4235. ; 141
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Journal article (peer-reviewed)abstract
- This study describes the construction of highly-sensitive photo-electrochemical (PEC) immunosensor for the detection of neuron-specific enolase (NSE). The biosensing platform is comprised of photo-active NiWO4 nanostructures, in-situ-grown over a conductive substrate (indium tin oxide) using a low-temperature template-based co-precipitation approach. The discussed approach enables the formation of discrete, yet morphologically-analogous, nanostructures with complete coverage (pinhole-free) of the electrode surface. The in-situ-grown nanostructure possess dense population with sharp saw-blade like morphological features that can support substantial immobilisation of anti-NSE agent. The constructed platform demonstrated excellent photo-catalytic activity towards uric acid (UA) which served as the base for the Electrochemical -mechanism (EC) based PEC inhibition sensing. The detection of NSE, relied on its obstruction in analytical signal observed for the photo-oxidation of UA after binding to the electrode surface via protein-antibody interaction. The constructed PEC immunosensor exhibits signal sensitivity up to 0.12 ng mL(-1) of NSE with excellent signal reproducibility and electrode replicability. Moreover, the constructed platform was successfully used for NSE determination in human serum samples.
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