A conductive hydrogel acting as a redox-active species was synthesized by crosslinking phytic acid as a ligand and lead(II) as the metal ion. The resulting gelatine-like material displays excellent redox activity and facilitates the transport of electrons and ions. Gold nanoparticles were electrochemically deposited on the hydrogel film, and antibody against cytokeratin antigen was immobilized thereon. An amperometric immunosensor for cytokeratin antigen 21–1 (CYFRA21-1), a kind of biomarker of lung cancer, was obtained by deposition of the composite on a glassy carbon electrode. If operated at ? 0.58 V (vs. Ag/AgCl), the sensor exhibits a linear detection range that extends from 50 fg mL?1 to 100 ng mL?1 CYFRA21-1, and a 38 fg mL?1 detection limit (at a signal to noise ratio of 3). The quantitation of CYFRA21-1 in (spiked) human serum samples showed satisfactory accuracy compared to an ELISA.
Graphical abstract A conductive hydrogel acting as a redox-active species was synthesized by crosslinking phytic acid as a ligand and lead(II) as the metal ion, which was used to fabricate an ultrasensitive label-free amperometric immunosensor for tumor marker.
The effect of ball milling process, co-doped seed and two step sintering technique on the properties of sol–gel derived alumina
abrasive sintered at low temperature was investigated. The results showed that ball milling time with 10 h can be effective
in enhancing the activity of the precursor and the microstructural uniformity of sintered alumina abrasive. A small amount
of Al2O3–(NH4)3AlF6 co-doped seed addition had potential synergistic effects for reducing α-Al2O3 phase transformation temperature and improving the mechanical property of alumina abrasive. A remarkable suppression of grain
growth was achieved by controlling sintering temperature with two-step sintering method. Therefore, by using ball milling
process, co-doping α-Al2O3–(NH4)3AlF6 seed and two-step sintering technique, the sol–gel derived uniform nanocrystalline alumina abrasive is easily achieved at
low temperature. Nanocrystalline alumina abrasive prepared at these conditions exhibited excellent mechanical properties and
wear resistance compared to fused corundum abrasive and those sol–gel derived corundum abrasive with conventional sintering
methods. 相似文献
X-ray tomography of samples containing both weakly and strongly absorbing materials are necessary in material and biomedical imaging. Extending the validity of the phase-attenuation duality (PAD) method, the propagation-based phase-contrast computed tomography (PPCT) of a sample with hybrid compositions of both the light and dense components with 60 keV of synchrotron radiation is investigated. The experimental results show that the PAD-based PPCT is effective in imaging both the weakly and strongly absorbing components simultaneously. Compared with the direct PPCT technique, the PAD-based PPCT technique demonstrates its excellent capability in material discrimination and characterization. In addition, the PAD-based PPCT exhibits a striking performance on the image contrast enhancement and noise suppression. Therefore, this technique is useful for material and biomedical imaging applications, especially when the radiation dose involved imposes a serious constraint. 相似文献
COVID-19 has spread around the world and caused serious public health and social problems. Although several vaccines have been authorized for emergency use, new effective antiviral drugs are still needed. Some repurposed drugs including Chloroquine, Hydroxychloroquine and Remdesivir were immediately used to treat COVID-19 after the pandemic. However, the therapeutic effects of these drugs have not been fully demonstrated in clinical studies. In this paper, we found an antimalarial drug, Naphthoquine, showed good broad-spectrum anti-coronavirus activity. Naphthoquineinhibited HCoV-229E, HCoV-OC43 and SARS-CoV-2 replication in vitro, with IC50 = 2.05 ± 1.44 μM, 5.83 ± 0.74 μM, and 2.01 ± 0.38 µM, respectively. Time-of-addition assay was also performed to explore at which stage Naphthoquine functions during SARS-CoV-2 replication. The results suggested that Naphthoquine may influence virus entry and post-entry replication. Considering the safety of Naphthoquine was even better than that of Chloroquine, we think Naphthoquine has the potential to be used as a broad-spectrum drug for coronavirus infection. 相似文献