A novel electrochemical sensing platform for detection of dopamine based on gold nanobipyramid/multi-walled carbon nanotube hybrids.

Dopamine homeostasis is an important clinical diagnostic index, because an abnormal level in the human body is closely related to certain serious diseases. Herein, a novel electrochemical sensing platform based on gold nanobipyramid/multi-walled carbon nanotube hybrids (AuNBP/MWCNTs) is developed to detect dopamine in human fluids. Using field emission scanning electron microscopy, it is observed that AuNBPs of about 60 nm with two pyramids are well dispersed on the surface of MWCNTs. Energy-dispersive X-ray spectrometry, X-ray diffraction and X-ray photoelectron spectroscopy confirm that AuNBPs are self-assembled onto the surface of MWCNTs to form the hybrids. Cyclic voltammetry reveals that the AuNBP/MWCNTs exhibit good electrocatalytic activity toward dopamine oxidation owing to the synergistic effects of AuNBPs and MWCNTs. In addition, both cyclic voltammetry and differential pulse voltammetry display three well-resolved and distinct oxidation peaks on the AuNBP/MWCNT-modified glassy carbon electrode. Based on AuNBP/MWCNTs, the newly developed electrochemical sensor is used to detect dopamine in the presence of ascorbic acid and uric acid over a wide linear range from 50 nM to 2.7 mM and a low detection limit of 15 nM (at S/N = 3). The electrochemical sensor can also be applied for the quantitative analysis of dopamine in real samples. Graphical abstract A novel electrochemical sensing platform based on gold nanobipyramid/multi-walled carbon nanotube hybrids (AuNBP/MWCNTs) was proposed to detect dopamine in the presence of ascorbic acid and uric acid.

Incorporating gold into nanocrystalline silver dressings reduces grain boundary size and maintains suitable antimicrobial properties.

Nanocrystalline silver dressings are widely known to be potent antimicrobial and anti-inflammatory agents and have long been used to treat topical wounds. Gold is known to be a strong anti-inflammatory agent and has been used in the treatment of rheumatoid arthritis for >70 years. The purpose of this work was to study the effect of incorporating gold into nanocrystalline silver dressings from antimicrobial and anti-inflammatory perspectives. Gold and silver dressing alloys were created by direct current magnetron sputtering and compared with pure silver nanocrystalline dressings using conventional biological (log reduction and corrected zone of inhibition) and physical (X-ray diffraction, X-ray photoelectron spectroscopy, energy-dispersive X-ray spectroscopy, atomic absorption spectroscopy, atomic force microscopy and scanning electron microscopy) characterisation techniques. While the gold/silver dressings were slightly weaker antimicrobials than the pure silver nanocrystalline structures, the addition of gold to the nanostructure reduces the minimum crystallite size from 17 to 4 nm. This difference increases the number of grain boundary atoms from 12% to 40% which could augment the anti-inflammatory properties of the dressings. The formation of gold oxide (Au2O3) was thought to be responsible for the observed decrease in crystallite size.

A scoping review on economic globalization in relation to the obesity epidemic.

This study reviewed evidence linking economic globalization to the obesity epidemic. Keyword/reference search was performed in PubMed, Web of Science, Cochrane Library, Scopus, EconLit, Google Scholar, and BMC Globalization and Health. A total of 16 studies were identified, in which six adopted a cross-sectional study design, nine adopted a longitudinal study design, and the remaining one adopted a case-control study design. Thirteen studies assessed the relationship between economic globalization and obesity at the country level, whereas the remaining three analyzed individual-level data. Fourteen studies found at least one aspect and/or measure of economic globalization to be positively associated with overweight/obesity, one found an inverse association, and the remaining one reported a null finding. Through market deregulation, tariff reduction, and investment liberalization, economic globalization tends to accelerate the market entry of modern food manufacturers, supermarket chains, and fast-food restaurants, resulting in substantially increased supply of high-sugar/fat energy-dense foods with enhanced variety and accessibility and reduced price. The potential impact of economic globalization on obesity through the adoption of modern workplace and domestic technologies and motorized transportation and through changes in social norms and culture were hypothesized in the literature but not empirically examined, which warrants future data-driven research.