7 research outputs found
Acetone Sensing and Catalytic Conversion by Pd-Loaded SnO2
Noble metal additives are widely used to improve the performance of metal oxide gas sensors, most prominently with palladium on tin oxide. Here, we photodeposit different quantities of Pd (0â3 mol%) onto nanostructured SnO2 and determine their effect on sensing acetone, a critical tracer of lipolysis by breath analysis. We focus on understanding the effect of operating temperature on acetone sensing performance (sensitivity and response/recovery times) and its relationship to catalytic oxidation of acetone through a packed bed of such Pd-loaded SnO2. The addition of Pd can either boost or deteriorate the sensing performance, depending on its loading and operating temperature. The sensor performance is optimal at Pd loadings of less than 0.2 mol% and operating temperatures of 200â262.5 °C, where acetone conversion is around 50%
Acetone Sensing and Catalytic Conversion by Pd-Loaded SnO2
Noble metal additives are widely used to improve the performance of metal oxide gas sensors, most prominently with palladium on tin oxide. Here, we photodeposit different quantities of Pd (0â3 mol%) onto nanostructured SnO2 and determine their effect on sensing acetone, a critical tracer of lipolysis by breath analysis. We focus on understanding the effect of operating temperature on acetone sensing performance (sensitivity and response/recovery times) and its relationship to catalytic oxidation of acetone through a packed bed of such Pd-loaded SnO2. The addition of Pd can either boost or deteriorate the sensing performance, depending on its loading and operating temperature. The sensor performance is optimal at Pd loadings of less than 0.2 mol% and operating temperatures of 200â262.5 °C, where acetone conversion is around 50%.ISSN:1996-194
Nd3+-Doped BiVO4 luminescent nanothermometers of high sensitivity
Neodymium-doped BiVO4nanoparticles are explored for luminescentnanothermometry in the first and second biological windows. Thenanothermometer sensitivity can be increased by an order of magnitudethrough careful selection of excitation wavelength and emission peaks,leading to sub-degree resolution and penetration depth up to 6 mm inbiological tissues.ISSN:1359-7345ISSN:1364-548
Simultaneous Nanothermometry and DeepâTissue Imaging
Bright, stable, and biocompatible fluorescent contrast agents operating in the second biological window (1000â1350 nm) are attractive for imaging of deepâlying structures (e.g., tumors) within tissues. Ideally, these contrast agents also provide functional insights, such as information on local temperature. Here, waterâdispersible barium phosphate nanoparticles doped with Mn5+ are made by scalable, continuous, and sterile flame aerosol technology and explored as fluorescent contrast agents with temperatureâsensitive peak emission in the NIRâII (1190 nm). Detailed assessment of their stability, toxicity with three representative cell lines (HeLa, THPâ1, NHDF), and deepâtissue imaging down to about 3 cm are presented. In addition, their high quantum yield (up to 34%) combined with excellent temperature sensitivity paves the way for concurrent deepâtissue imaging and nanothermometry, with biologically wellâtolerated nanoparticles.ISSN:2198-384
Precision in Thermal Therapy: Clinical Requirements and Solutions from Nanotechnology
The heating of diseased tissue as a therapeutic measure has gained increased clinical attention, mostly due to its targetâspecificity that minimizes side effects. However, to ensure a successful therapy, heating has to be homogeneous and highly localized, as well as, within a certain temperature range. Therefore, precise control over thermal treatments is a clinical prerequisite to minimize treatment and safety margins. Although this requirement is mentioned frequently, past research has focused predominantly on improving thermometry resolution and heating efficiency through tedious material optimization. Here, current clinical applications of thermal therapy with their challenges are first highlighted, especially with respect to treatment control and margins. Thereafter, it is quantitatively shown that clinically available thermometry fulfills the requirements and future research should focus on achieving better temperature control instead. With nanotechnology, novel strategies based on selfâlimiting nanoparticle systems and particleâbased thermometers with active feedâback control have also become available and are discussed. All of these approaches are systematically compared and analyzed with respect to their clinical applicability. The extent to which control over thermal therapy is necessary is also discussed alongside a presentation of the existing methods which fulfill the set requirements for clinical success and what issues remain to be tackled by research in the near future.ISSN:2366-398