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Effective water use is currently a critical global challenge needed to prevent water shortages and has attracted significant research attention. The realization of solar-driven water evaporation by using effective converters has attracted considerable attention in recent years owing to its potential for seawater desalination and wastewater treatment. Consequently, this paper proposes a simple two-step method to prepare low-cost and self-floating photothermal converters from waste coffee grounds. First, the coffee grounds were carbonized at 1,000 °C to develop broadband absorption, and the carbonized coffee grounds were modified using hydrophobic silane to enhance the water-floatation property of the grounds. The prepared hydrophobic carbonized coffee grounds exhibited good performance for desalination and water purification under sunlight irradiation. The self-floatation ability, low cost, well solar evaporation performance, and easy preparation contribute to the promising potential of using hydrophobic carbonized coffee grounds infuture steps toward eco-friendly desalination procedures. [ABSTRACT FROM AUTHOR]

The geometry of resonant absorbers (RA) is varied by tryptic digestion to design a probe platform. The process includes fabrication of a line array of poly(methacrylic acid) (PMAA) brush as an RA, tailed by the immobilization of gelatin. The gelatin-modified PMAA RA is a kind of one-dimensional plasmonic grating, possessing an optical feature with a characteristic absorption peak. The growth of gelatin on PMAA RA resulted in a blue shift of the absorption peak from 465 to 263 nm. Trypsin catalyzes the hydrolysis of peptide bonds, breaking down gelatin into smaller peptides causing the change in geometry of RA. The gelatin of RA was digested in a wide linear range of activity of trypsin from 34 to 1088 U mL−1 resulting in a red shift of the absorption peak of RA from 263 to 474 nm within 10 min. The limit of detection achieved is 11 U mL−1 with ca. 1.9% standard deviation and 101.4% recovery of spiked serum samples. The chemical selectivity of the trypsin assay is evidenced by motoring the changes in a shift of the absorption peak of gelatin-modified PMAA RA using chymotrypsin and horseradish peroxidase. [ABSTRACT FROM AUTHOR]

A low operating temperature CO (carbon monoxide) sensor was fabricated from a nanometer-scale SnO2 (tin oxide) powder. The SnO2 nanoparticles in a size range 10-20 nm were synthesized as a function of surfactant (tri-n-octylamine, TOA) addition (0-1.5 mol%) via a simple thermal decomposition method. The resulting SnO2 nanoparticles were first screen-printed onto an electrode patterned substrate to be a thick film. Subsequently, the composite film was heat-treated to be a device for sensing CO gas. The thermal decomposed powders were characterized by field-emission scanning electron microscopy (FESEM), X-ray diffractometry (XRD), and surface area measurements (BET). The CO-sensing performance of all the sensors was investigated. The experimental results showed that the TOA addition significantly decreased the particle size of the resulting SnO2 nanoparticle. However, the structure of the powder coating was crucial to their sensing performance. After heat-treatment, the smaller particle tended to cause the formation of agglomeration, resulting in the decline of surface area and reducing the reaction site during sensing. However, the paths for the sensed gas entering between the agglomerated structure may influence the sensing performance. As a CO sensing material, the SnO2 nanoparticle (~12 nm in diameter) prepared with 1.25 mol% TOA addition exhibited most stable electrical performance. The SnO2 coating with TOA addition >0.75 mol% exhibited sensor response at a relatively low temperature of <50°C. [ABSTRACT FROM AUTHOR]

We report the development of Herceptin-conjugated fluorescent polymeric nanoparticles (PNp) probes. Synthesis of fluorescent conjugated polymer as the core, preparation of the core/shell PNp, the ability of immobilizing Herceptin on PNp, targeting and imaging of bioconjugated PNp toward HER2-overexpressing cancer cells, and therapeutic effect on cell cycle, together with the expression of apoptosis related proteins, were investigated. We have achieved active tumor targeting by rapid PNp-antibody binding to tumor-specific antigens. Besides, Herceptin-conjugated PNp can suppress the growth of HER2-overexpressing cancer cells. [ABSTRACT FROM AUTHOR]

A thermal stimulated current (TSC) spectrometer was used to study the trap characteristics of photorefractive polymeric materials in this article. In addition to normal positive peaks due to segmental disorientation induced depolarization, there were negative peaks, even after a prior annealing treatment above Tg without electrical field to release the intrinsically trapped carriers in the film. The negative peaks of the photorefractive polymer containing the hole transport material probably resulted from the release of the trapped field-induced positive carriers during polarization. The negative peak enables trap characteristics to be distinguished from the segmental disorientation behavior. It also makes TSC a useful tool to study the trap characteristics of photorefractive polymers containing organic conducting materials with hole carrier domination in transportation. Incorporating different components into the film caused the change of trap behaviors. The charge transport material (CTM) incorporating in the nonlinear optical (NLO) material PMDA-DR19 reduced the trap depth and transformed the NLO material from nonphotoconductive to photoconductive. Adding charge generating material (CGM) generated an additional shallow trap by which the photogenerated electron-hole pairs were separated and the trapped holes were released more easily. The photorefractive composites with aromatic polyester hosts PMDA-DR19 and IPA-DR19 exhibited deeper trap depth and higher trap density than that with AA-DR19 host from aliphatic diacid. IPA-DR19/PVB/CTM, containing no carboxyl acid groups, possessed the same total trap density as PMDA-DR19/PVB/CTM, but the former exhibited a larger part of low energy traps than the latter did. [ABSTRACT FROM AUTHOR]