| 1. |
- Abdullah, Muhammad Imran, et al.
(author)
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Quantum Chemical Designing of Efficient Sensitizers for Dye Sensitized Solar Cells
- 2013
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In: Bulletin of the Korean Chemical Society (Print). - : Korean Chemical Society. - 0253-2964 .- 1229-5949. ; 34:7, s. 2093-2098
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Journal article (peer-reviewed)abstract
- Density functional theory (DFT) was used to determine the ground state geometries of indigo and new design dyes (IM-Dye-1 IM-Dye-2 and IM-Dye-3). The time dependant density functional theory (TDDFT) was used to calculate the excitation energies. All the calculations were performed in both gas and solvent phase. The LUMO energies of all the dyes were above the conduction band of TiO2, while the HOMOs were below the redox couple (except IM-Dye-3). The HOMO-LUMO energy gaps of new design dyes were smaller as compared to indigo. All new design dyes were strongly red shifted as compared to indigo. The improved light harvesting efficiency (LHE) and free energy change of electron injection Delta G(inject) of new designed sensitizers revealed that these materials would be excellent sensitizers. The broken coplanarity between the benzene near anchoring group having LUMO and the last benzene attached to TPA unit in all new design dyes consequently would hamper the recombination reaction. This theoretical designing will the pave way for experimentalists to synthesize the efficient sensitizers for solar cells.
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| 2. |
- Willander, Magnus, et al.
(author)
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Applications of Zinc Oxide Nanowires for Bio-photonics and Bio-electronics
- 2011
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In: Proceedings of SPIE Volume 7940. - Bellingham, Washington, USA : SPIE - International Society for Optical Engineering. - 9780819484772
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Conference paper (other academic/artistic)abstract
- Using zinc oxide (ZnO) nanostructures, nanorods (NRs) and nanoparticles (NPs) grown on different substrates (sub-micrometer glass pipettes, thin silver wire and on plastic substrate) different bio-sensors were demonstrated. The demonstrated sensors are based on potentiometric approach and are sensitive to the ionic metals and biological analyte in question. For each case a selective membrane or enzyme was used. The measurements were performed for intracellular environment as well as in some cases (cholesterol and uric acid). The selectivity in each case is tuned according to the element to be sensed. Moreover we also developed photodynamic therapy approach based on the use of ZnO NRs and NPs. Necrosis/apoptosis was possible to achieve for different types of cancerous cell. The results indicate that the ZnO with its UV and white band emissions is beneficial to photodynamic therapy technology.
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| 3. |
- Asif, Muhammad, et al.
(author)
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Functionalized ZnO nanorod-based selective magnesium ion sensor for intracellular measurements
- 2010
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In: Biosensors & bioelectronics. - : Elsevier Science B.V., Amsterdam.. - 0956-5663 .- 1873-4235. ; 26:3, s. 1118-1123
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Journal article (peer-reviewed)abstract
- ZnO nanorods were grown on a silver-coated tip of a borosilicate glass capillary (0.7 mu m in tip diameter) and used as selective potentiometric sensor of intracellular free Mg2+. To functionalize the ZnO nanorods for selectivity of Mg2+, a polymeric membrane with Mg2+-selective ionophores were coated on the surface of the ZnO nanorods. These functionalized ZnO nanorods exhibited a Mg2+-dependent electrochemical potential difference versus an Ag/AgCl reference microelectrode within the concentration range from 500 nM to 100 mM. Two types of cells, human adipocytes and frog oocytes, were used for the intracellular Mg2+ measurements. The intracellular concentration of free Mg2+ in human adipocytes and frog oocytes were 0.4-0.5 and 0.8-0.9 mM, respectively. Such type of nanoelectrode device paves the way to enable analytical measurements in single living cells and to sense other bio-chemical species at the intracellular level.
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| 4. |
- Asif, Muhammad H, et al.
(author)
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Functionalised ZnO-nanorod-based selective electrochemical sensor for intracellular glucose
- 2010
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In: Biosensors & Bioelectronics. - : Elsevier BV. - 1873-4235 .- 0956-5663. ; 25:10, s. 2205-2211
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Journal article (peer-reviewed)abstract
- In this article, we report a functionalised ZnO-nanorod-based selective electrochemical sensor for intracellular glucose. To adjust the sensor for intracellular glucose measurements, we grew hexagonal ZnO nanorods on the tip of a silver-covered borosilicate glass capillary (0.7 mu m diameter) and coated them with the enzyme glucose oxidase. The enzyme-coated ZnO nanorods exhibited a glucose-dependent electrochemical potential difference versus an Ag/AgCl reference microelectrode. The potential difference was linear over the concentration range of interest (0.5-1000 mu M). The measured glucose concentration in human adipocytes or frog oocytes using our ZnO-nanorod sensor was consistent with values of glucose concentration reported in the literature; furthermore, the sensor was able to show that insulin increased the intracellular glucose concentration. This nanoelectrode device demonstrates a simple technique to measure intracellular glucose concentration. (C) 2010 Elsevier B.V. All rights reserved.
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| 5. |
- Fulati, Alimujiang, 1981-, et al.
(author)
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An intracellular glucose biosensor based on nanoflake ZnO
- 2010
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In: Sensors and actuators. B, Chemical. - : Elsevier. - 0925-4005 .- 1873-3077. ; 150:2, s. 673-680
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Journal article (other academic/artistic)abstract
- In this study, an improved potentiometric intracellular glucose biosensor was fabricated with immobilization of glucose oxidase on a ZnO nanoporous material. The ZnO nanoporous material with a wall thickness around 200 nm was grown on the tip of a borosilicate glass capillary and used as a selective intracellular glucose sensor for the measurement of glucose concentrations in human adipocytes and frog oocytes. The results showed a fast response within 4 s and a linear glucosedependent electrochemical response over a wide range of glucose concentration (500 nM-10 mM). The measurements of intracellular glucose concentrations with our biosensor were consistent with the values of intracellular glucose concentrations reported in the literature. The sensor also demonstrated its capability by detecting an increase in the intracellular glucose concentration induced by insulin. We found that the ZnO nanoporous material provides sensitivity as high as 1.8 times higher than that obtained using ZnO nanorods under the same conditions. Moreover, the fabrication method in our experiment is simple and the excellent performance of the developed nanosensor in sensitivity, stability, selectivity, reproducibility and anti-interference was achieved. All these advantageous features of this intracellular glucose biosensor based on functionalised ZnO nanoporous material compared to ZnO nanorods demonstrate a promising way of enhancing glucose biosensor performance to measure reliable intracellular glucose concentrations within single living cells.
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| 6. |
- Peden, John F., et al.
(author)
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A genome-wide association study in Europeans and South Asians identifies five new loci for coronary artery disease
- 2011
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In: Nature Genetics. - : Springer Science and Business Media LLC. - 1061-4036 .- 1546-1718. ; 43:4, s. 339-344
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Journal article (peer-reviewed)abstract
- Genome-wide association studies have identified 11 common variants convincingly associated with coronary artery disease (CAD)(1-7), a modest number considering the apparent heritability of CAD(8). All of these variants have been discovered in European populations. We report a meta-analysis of four large genome-wide association studies of CAD, with similar to 575,000 genotyped SNPs in a discovery dataset comprising 15,420 individuals with CAD (cases) (8,424 Europeans and 6,996 South Asians) and 15,062 controls. There was little evidence for ancestry-specific associations, supporting the use of combined analyses. Replication in an independent sample of 21,408 cases and 19,185 controls identified five loci newly associated with CAD (P < 5 x 10(-8) in the combined discovery and replication analysis): LIPA on 10q23, PDGFD on 11q22, ADAMTS7-MORF4L1 on 15q25, a gene rich locus on 7q22 and KIAA1462 on 10p11. The CAD-associated SNP in the PDGFD locus showed tissue-specific cis expression quantitative trait locus effects. These findings implicate new pathways for CAD susceptibility.
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| 7. |
- Qi, Qibin, et al.
(author)
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FTO genetic variants, dietary intake and body mass index : insights from 177 330 individuals
- 2014
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In: Human Molecular Genetics. - : Oxford University Press (OUP). - 0964-6906 .- 1460-2083. ; 23:25, s. 6961-6972
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Journal article (peer-reviewed)abstract
- FTO is the strongest known genetic susceptibility locus for obesity. Experimental studies in animals suggest the potential roles of FTO in regulating food intake. The interactive relation among FTO variants, dietary intake and body mass index (BMI) is complex and results from previous often small-scale studies in humans are highly inconsistent. We performed large-scale analyses based on data from 177 330 adults (154 439 Whites, 5776 African Americans and 17 115 Asians) from 40 studies to examine: (i) the association between the FTO-rs9939609 variant (or a proxy single-nucleotide polymorphism) and total energy and macronutrient intake and (ii) the interaction between the FTO variant and dietary intake on BMI. The minor allele (A-allele) of the FTO-rs9939609 variant was associated with higher BMI in Whites (effect per allele = 0.34 [0.31, 0.37] kg/m(2), P = 1.9 × 10(-105)), and all participants (0.30 [0.30, 0.35] kg/m(2), P = 3.6 × 10(-107)). The BMI-increasing allele of the FTO variant showed a significant association with higher dietary protein intake (effect per allele = 0.08 [0.06, 0.10] %, P = 2.4 × 10(-16)), and relative weak associations with lower total energy intake (-6.4 [-10.1, -2.6] kcal/day, P = 0.001) and lower dietary carbohydrate intake (-0.07 [-0.11, -0.02] %, P = 0.004). The associations with protein (P = 7.5 × 10(-9)) and total energy (P = 0.002) were attenuated but remained significant after adjustment for BMI. We did not find significant interactions between the FTO variant and dietary intake of total energy, protein, carbohydrate or fat on BMI. Our findings suggest a positive association between the BMI-increasing allele of FTO variant and higher dietary protein intake and offer insight into potential link between FTO, dietary protein intake and adiposity.
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| 8. |
- Usman Ali, Syed, et al.
(author)
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Intracellular K+ Determination With a Potentiometric Microelectrode Based on ZnO Nanowires
- 2011
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In: IEEE Transactions on Nanotechnology. - : IEEE. - 1536-125X .- 1941-0085. ; 10:4, s. 913-919
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Journal article (peer-reviewed)abstract
- The fabrication and application of an intracellular K+-selective microelectrode is demonstrated. ZnO nanowires with a diameter of 100-180 nm and a length of approximately 1.5. m are grown on a borosilicate glass microcapillary. The ZnO nanowires were coated by a K+-ionophore-containing membrane. The K+-selective microelectrode exhibited a K+-dependent potentiometric response versus an Ag/AgCl reference microelectrode that was linear over a large concentration range (25 . M-125 mM) with a minimum detection limit of 1 . M. The measured K+ concentrations in human adipocytes and in frog oocytes were consistent with values of K+ concentrations reported in the literature. The sensor has several advantages including ease of fabrication, ease of insertion into the cells, low cost, and high selectivity features that make this type of sensor suitable to characterize physiologically relevant ions within single living cells.
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