摘要 :
The ability to mimic protein-based oxidase with multi-functional inorganic nanozymes would greatly advance biomedical and clinical practices. Praseodymia (PrOx) nanorods (NRs) and nanoparticles (NPs) have been syn-thesized using h...
展开
The ability to mimic protein-based oxidase with multi-functional inorganic nanozymes would greatly advance biomedical and clinical practices. Praseodymia (PrOx) nanorods (NRs) and nanoparticles (NPs) have been syn-thesized using hydrothermal and precipitation methods. Both PrOx catalysts with different morphologies exhibit significantly higher oxidase-like activities (Michaelis-Menten constant Km 收起
摘要 :
Nanostructured ceria-praseodymia catalysts with different praseodymium contents have been prepared through hydrothermal synthesis to study the effect of Pr as a dopant and the effect of morphology towards soot combustion under "lo...
展开
Nanostructured ceria-praseodymia catalysts with different praseodymium contents have been prepared through hydrothermal synthesis to study the effect of Pr as a dopant and the effect of morphology towards soot combustion under "loose" and "tight" soot-catalyst conditions. Samples synthesized through solution combustion synthesis (SCS) have also been prepared as comparative materials. Studies in physicochemical properties of the catalysts have been carried out using complementary techniques. The present work also resorts to soot-TPR as an unconventional method of investigating the ability of solid catalysts to initiate soot oxidation in the absence of bulk oxygen. Ce50Pr50 catalyst (where 50 indicates the atomic percentage of cerium as well as of praseodymium) with mixed structures of nanorods and nanocubes has attained the best catalytic performances, thanks to the high lattice oxygen mobility and the easy reducibility. The insertion of Pr cations, to the ceria framework enhances the number of redox sites on the surface, thus generating more oxygen vacancies. As a whole, activity tests in general have proven that despite having relatively low surface areas, ceria-praseodymia nanocubes and nanorods facilitated soot combustion reaction more actively than SCS-based ceria-praseodymia catalysts with larger surface areas. This evidences the beneficial effect of well-defined nanostructures in soot combustion, due to their possession of highly reactive low-index facets (1 0 0) and (1 10). Within SCS-based samples, however, the specific surface area overshadows the importance of praseodymium. This eventually marks the synergistic combination of well-defined nanostructures and praseodymium as a dopant. (C) 2015 Elsevier B.V. All rights reserved.
收起
摘要 :
? 2022 Elsevier B.V.The ubiquitous presence of ochratoxin A (OTA), a toxic food contaminant, requires development of fast and sensitive detection tools. However, it is difficult to find a method that can address high sensitivity a...
展开
? 2022 Elsevier B.V.The ubiquitous presence of ochratoxin A (OTA), a toxic food contaminant, requires development of fast and sensitive detection tools. However, it is difficult to find a method that can address high sensitivity and wide detection range simultaneously. In this work, a sensing platform composed of praseodymia nanorods (Pr6O11-NRs) and aptamers for OTA is established. Under the dual-readout modes, this platform provides a highly sensitive detection of OTA with extra-wide range, over three orders of magnitude with limit of detection (LOD) of 0.8 ng/mL. Both fluorometric and colorimetric signals were obtained because of the excellent fluorescent quenching and oxidase-like activity of Pr6O11-NRs. This probe enables a detection range of OTA which covers the maximum acceptable levels of most foods. Real samples were tested with this method, demonstrating high sensitivity and good recoveries. This sensing strategy has great potential for an expanded application in point-of-care detection of other toxins via portable devices.
收起
摘要 :
Nanozymes based on rare earth oxides such as ceria have been promising as new non-antibiotic bactericidal tools. The activities of praseodymia mimicking both oxidase and peroxidase were examined which led to excellent oxidative ca...
展开
Nanozymes based on rare earth oxides such as ceria have been promising as new non-antibiotic bactericidal tools. The activities of praseodymia mimicking both oxidase and peroxidase were examined which led to excellent oxidative capacity in generating species such as holes and hydroxyl radicals. The antibacterial performance of praseodymia nanorods from precipitation method was investigated in comparison with commercial samples. Incubation of praseodymia with E. Coli results in significant reduction of bacterial proliferation in both swarming and inhibition experiments, but not with S. aureus. This could potentially provide a new bactericidal strategy to combat abiotic or strain-selective drug resistance in future applications.
收起
原文获取