To fabricate high-density cobalt-based catalysts, we first synthesized SiO]C composites via a hydrother- mad method and removed C and SiO2 by two different methods, respectively. The as-prepared SiO2 and C supports th...To fabricate high-density cobalt-based catalysts, we first synthesized SiO]C composites via a hydrother- mad method and removed C and SiO2 by two different methods, respectively. The as-prepared SiO2 and C supports then reacted with cobalt acetylacetonate and N,N-dimethylformamide（DMF） under hydrothermal conditions to prepare SiO2/Co and C/Co nanocomposite catalysts. The catalysts were characterized by X-ray difffaction（XRD）, scanning electron microscope（SEM）, transmission electron microscopy（TEM）, inductively coupled plasma mass spectrometry（ICP）~ energy dispersive X-ray fiuoresence spectrometer（EDX）, and nitrogen adsorption. It was found that hexagonal cobalt nanocrystals were successfully integrated with the mesoporous silica or carbon nanotube supports. SEM and TEM results show that SiO2/Co composites with a hollow/mesoporous sphere structure and C/Co composites with a tubular structure have been successfully synthesized. Both composite samples show superpara- magnetism exhibiting an S-type hysteresis loop, which originated from the cobalt nanoparticles in the samples. Nitrogen adsorption/desorption curves suggest that the SiO2 and C supports have well-developed pore structures and large specific surface areas, and the loading and good dispersity of cobalt nanoparticles on the supports were proven by ICP and EDX. Moreover, the samples exhibited good and stable catalytic activity, denlonstrating that the two composites are suitable catalysts for Fischer-Tropsch CO2 hydrogenation.展开更多
ABSTRACT The efficient detection of tumor markers is crucial to early cancer diagnosis and monitoring.Here,we propose a unique“two birds with one stone”dissolution-enhanced afterglow bioassay based on amino-function...ABSTRACT The efficient detection of tumor markers is crucial to early cancer diagnosis and monitoring.Here,we propose a unique“two birds with one stone”dissolution-enhanced afterglow bioassay based on amino-functionalized mesoporous SiO2 nanoparticles(MSNs-NH2)encapsulated Eu(OH)CO_(3)nanoprobes.These nanoprobes(i)stably conjugate to the antibody and(ii)are highly soluble in the acidic enhancer solution,and provide a high Eu3+concentration.The released Eu3+ions further activate the photochemical afterglow system to determine the alpha-fetoprotein(AFP)levels in clinical serum samples.Without the use of a real-time excitation source,the interference of autofluorescence and scattering from blood can be avoided.The demonstrated limit of detection(LOD)for AFP was as low as 0.12 ng·mL^(−1).This covalently connected dissolution-enhanced luminescent bioassay(DELBA)and novel afterglow system shows tremendous potential for ultrasensitive and rapid clinical diagnosis.展开更多
基金Supported by the Natural Science Foundation of Heilongjiang Province, China（No.B20170001）, the Postdoctoral Fund of Heilongjiang Province, China（No.LBH-Z16009）, the Fundamental Research Funds for the Central Universities, China（No. 2572018BC28） and the Postdoctoral Science Foundation of China（Nos.2016M591501, 2017T100218）.
文摘To fabricate high-density cobalt-based catalysts, we first synthesized SiO]C composites via a hydrother- mad method and removed C and SiO2 by two different methods, respectively. The as-prepared SiO2 and C supports then reacted with cobalt acetylacetonate and N,N-dimethylformamide（DMF） under hydrothermal conditions to prepare SiO2/Co and C/Co nanocomposite catalysts. The catalysts were characterized by X-ray difffaction（XRD）, scanning electron microscope（SEM）, transmission electron microscopy（TEM）, inductively coupled plasma mass spectrometry（ICP）~ energy dispersive X-ray fiuoresence spectrometer（EDX）, and nitrogen adsorption. It was found that hexagonal cobalt nanocrystals were successfully integrated with the mesoporous silica or carbon nanotube supports. SEM and TEM results show that SiO2/Co composites with a hollow/mesoporous sphere structure and C/Co composites with a tubular structure have been successfully synthesized. Both composite samples show superpara- magnetism exhibiting an S-type hysteresis loop, which originated from the cobalt nanoparticles in the samples. Nitrogen adsorption/desorption curves suggest that the SiO2 and C supports have well-developed pore structures and large specific surface areas, and the loading and good dispersity of cobalt nanoparticles on the supports were proven by ICP and EDX. Moreover, the samples exhibited good and stable catalytic activity, denlonstrating that the two composites are suitable catalysts for Fischer-Tropsch CO2 hydrogenation.
基金National Key R&D Program of China(No.2017YFA0205100)the National Natural Science Foundation of China(No.22101052)for financial support.
文摘ABSTRACT The efficient detection of tumor markers is crucial to early cancer diagnosis and monitoring.Here,we propose a unique“two birds with one stone”dissolution-enhanced afterglow bioassay based on amino-functionalized mesoporous SiO2 nanoparticles(MSNs-NH2)encapsulated Eu(OH)CO_(3)nanoprobes.These nanoprobes(i)stably conjugate to the antibody and(ii)are highly soluble in the acidic enhancer solution,and provide a high Eu3+concentration.The released Eu3+ions further activate the photochemical afterglow system to determine the alpha-fetoprotein(AFP)levels in clinical serum samples.Without the use of a real-time excitation source,the interference of autofluorescence and scattering from blood can be avoided.The demonstrated limit of detection(LOD)for AFP was as low as 0.12 ng·mL^(−1).This covalently connected dissolution-enhanced luminescent bioassay(DELBA)and novel afterglow system shows tremendous potential for ultrasensitive and rapid clinical diagnosis.
