Background Rapid immunochromatographic tests can detect disease markers in 10–15 minutes, which facilitates clinical diagnosis and treatment programs. However, most immunochromatographic tests employ gold nanoparticles as reporters, and these have only moderate sensitivity and act as qualitative methods for analyzing high biomarker concentrations. Methods In this study, we introduce quantum dots (QDs) as fluorescent probes and immunochromatographic strips to develop quantitative fluorescence point-of-care tests (QF-POCT) to analyze C-reactive protein (CRP) levels. Goat anti-rabbit IgG and rabbit IgG were used as control antibodies, and mouse monoclonal CRP antibody pairs were used for disease marker detection. One monoclonal CRP antibody was conjugated with QDs and served as a signal antibody, and the other monoclonal CRP antibody was dispensed onto the nitrocellulose membrane and served as a capturing antibody. In the presence of CRP, the fluorescence intensity of the monoclonal antibody-CRP-monoclonal antibody sandwich complex captured on the nitrocellulose membrane was determined using the fluorescence strip reader. Results QF-POCT assays could quantitatively analyze the concentration of CRP in 15 minutes had a detection limit of 0.25 mg/L, and had a wide detection linearity range (0.5–300 mg/L). The intra-assay and interassay coefficients of variation were 8.95% and 9.86% at 0.5 mg/L, 6.47% and 8.66% at 10 mg/L, and 6.81% and 9.10% at 60 mg/L, respectively. In a comparison between clinical samples, the results of this QD-based assay of CRP levels were significantly correlated with those of an Immulite 2000 assay ( R =0.993, P <0.001). Conclusion Our results demonstrated that the QD-based immunochromatographic test is a rapid, sensitive, accurate, and quantitative method for the detection of disease biomarkers.

A large amount of hazardous tar residue is produced during the synthesis of rubber vulcanization accelerator 2-mercaptobenzothiazole (MBT). In this study, pyrite (FeS 2 ) was used as catalyst for the hydrogenation of the tar residue under different conditions. Optimal hydrogenation conditions were as follows: 270°C under an H 2 pressure of 4.5 MPa for 8 h under a catalyst loading of 2%. MBT presented in tar residue is converted to benzothiazole (BT) by a high yielding hydrogenation in 86.9% yield based on the initial amount of BT with a small quantity aniline also produced as side product. This work provides a framework for possible ways to treat the toxic tar residue formed in the industrial synthesis of BT through the hydrogenation procedure established in this study.

This study investigated the electronic structure of SrTi1-xVxO3 (STVO) thin films, which are solid solutions of strongly correlated transparent conductive oxide (TCO) SrVO3 and oxide semiconductor SrTiO3, using in situ photoemission spectroscopy. STVO is one of the most promising candidates for correlated-metal TCO because it has the capability of optimizing the performance of transparent electrodes by varying x. Systematic and significant spectral changes were found near the Fermi level (EF) as a function of x, while the overall electronic structure of STVO is in good agreement with the prediction of band structure calculations. As x decreases from 1.0, spectral weight transfer occurs from the coherent band near EF to the incoherent states (lower Hubbard band) around 1.0-1.5 eV.Simultaneously, a pseudogap is formed at EF, indicating a significant reduction in quasiparticle spectral weight within close vicinity of EF. This pseudogap seems to evolve into an energy gap at x = 0.4, suggesting the occurrence of a composition-driven metal-insulator transition. From angleresolved photoemission spectroscopic results, the carrier concentration n changes proportionally as a function of x in the metallic range of x = 0.6-1.0. In contrast, the mass enhancement factor, which is proportional to the effective mass (m*), does not change significantly with varying x. These results suggest that the key factor of n/m* in optimizing the performance of correlated-metal TCO is tuned by x, highlighting the potential of STVO to achieve the desired TCO performance in the metallic region.

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Soil matric potential is an important parameter for agricultural and environmental research and applications. In this study, we developed a novel sensor to determine fast and in-situ the soil matric potential. The probe of the soil matric potential sensor comprises a perforated coaxial stainless steel cylinder filled with a porous material (gypsum). With a pre-determined gypsum water retention curve, the probe can determine the gypsum matric potential through measuring its water content. The matric potential of soil surrounding the probe is inferred by the reading of the sensor after the soil reaches a hydraulic equilibrium with the gypsum. The sensor was calibrated by determining the gypsum water retention curve using a pressure plate method and tested in three soil samples with different textures. The results showed that the novel sensor can determine the water retention curves of the three soil samples from saturated to dry when combined with a soil water content sensor. The novel sensor can respond fast to the changes of the soil matric potential due to its small volume. Future research could explore the application for agriculture field crop irrigation.