Natural cellulose molecules have a strong tendency of being aggregated into larger structures. Thus, the imaging of isolated individual cellulose molecules is hampered for a long time. In this work, we manage to observe, for the first time, the isolated individual natural cellulose chains on a sample surface by means of atomic force microscope. The advantage of the ionic liquid, in which natural cellulose can be molecularly dispersed, is considered to be the key point for the successful imaging. Moreover, we find that the surface charge can influence the morphology of the single cellulose chains upon adsorption. That is, on the positively charged surface, individual cellulose chains adopt an extended conformation; whereas on the negatively charged surface, a compact globule conformation is observed.

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In this study, an interesting phenomenon was found where cells (including tumor and normal cells) managed to significantly enhance chemiluminescence (CL) signals. The possible reaction mechanism may be that cells can be severely damaged by CL substrates, and the released contents, possibly proteins (such as cytochrome c), can remarkably magnify CL owing to the increased production of singlet oxygen. More importantly, based on the above phenomena, a novel cell-assisted enhanced CL strategy was proposed for the rapid and label-free detection of tumor cells. The complexes of aptamer sgc8c and streptavidin-modified magnetic beads were employed to recognize and isolate target tumor cells from whole blood. The enhanced CL intensity, which was triggered directly by the captured cells, was measured. The proposed strategy exhibited a good detection performance with a linear range from 200 to 10,000 cells/mL. The analysis can be finished in ∼30 min, and the limit of detection was down to 100 cells/mL. The recoveries and relative standard deviations were 97.81–102.71% and 3.46–12.71%, respectively. Moreover, the established method can successfully distinguish the leukemia patients from healthy people. Therefore, it provides a novel, rapid, and simple method for the determination of tumor cells, which can be used in further practice.

First-principles calculations and climbing-image nudged elastic band method were used to investigate the effects of Mo alloying on the structural stability, mechanical properties, and hydrogen-diffusion behavior of Nb.