| 1. |
- Abbas, Malik Waseem, et al.
(författare)
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Carbon quantum dot coated Fe3O4 hybrid composites for sensitive electrochemical detection of uric acid
- 2019
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Ingår i: Microchemical journal (Print). - : ELSEVIER SCIENCE BV. - 0026-265X .- 1095-9149. ; 146, s. 517-524
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Tidskriftsartikel (refereegranskat)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. |
- Shahriari, Mohammad, 1945, et al.
(författare)
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Risk Management as a Tool to Protect Water resources
- 2010
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Ingår i: International Sustainable Water and Wastewater Management Symposium Proceedings, 26-28 October, Konya, Turkey.
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Konferensbidrag (refereegranskat)abstract
- ABSTRACT:Water pollution is a global problem, and could have negative impacts on ecosystems, food production, health, and economic activities. The pollutants may have severe impacts on the usefulness and value of water resources. Presence of hazardous substances, poor monitoring and control, improper handling and treatment of wastes as well as misuse of water could be considered as the main causes for pollution of water resources. Furthermore, climate change, increasing of human population and the unprecedented urbanization and industrialization of the developing countries will make the situation worse in terms of pollution and consequently shortage of freshwater resources. Indeed water shortage is very often induced by water pollution. One of the biggest challenges in 21st century will be access to freshwater. Note that more than one billion people still have no access to clean drinking water, while approximately two and a half billion do not have adequate sanitation services. Due to the abovementioned problem a global attempts is needed to be put to protect and save the water resources. Now the question is: What shall we do to protect or save the water sources? In order to protect the water resources the following questions should be answered:•What are the hazardous substances/contaminants as the causes of pollution? •What are acceptable rate of the contaminants?•Where the pollution substances are generated?•How hazardous substances could reach the water resources? •How the pollution could be prevented or how the effects of hazardous substances could be minimized to the acceptable level? A model has been developed by which the risk of water polluters could be identified and minimized. A case has been selected to see how the model works. It was found that the model accompanied by cause effect analysis procedure and weighting risk factors is capable of ranking the existing risks regarding the contaminated wastes in an area. Furthermore it was found that reducing risk levels could be achieved as the model considers the most important problems related to the environment.
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| 3. |
- Soomro, Razium Ali, et al.
(författare)
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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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Ingår i: Biosensors & bioelectronics. - : ELSEVIER ADVANCED TECHNOLOGY. - 0956-5663 .- 1873-4235. ; 141
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Tidskriftsartikel (refereegranskat)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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