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The enzymolytic preparation of cellulose nanocrystals (CNCs) has the unique advantages due to its green chemistry process. In this work, the cotton pulp fibers were enzymolyzed with the cellulase to prepare the ribbon-like CNC, and the samples were characterized by SEM, FTIR, XRD and DLS. The results indicated the CNC with the length 250-900 nm and width 30-45 nm could be produced from cotton pulp fibers at the lower cellulase concentration, the time 5-11 h and temperature 50 ºC. When the cellulase concentration rose up to 100 /ml, the granular CNC appeared, and at 300 μ/ml all of the formed CNC were granular. FTIR and XRD analyses proved that the ribbon-like CNC had the same crystal style and chemical structure with original cotton pulp fibers, but its crystallinity was weakened slightly. Despite the fact that there are the weakened crystallinity and aggregates, the as-prepared samples were still called as CNCs for simplicity. In addition, the article has discussed the mechanism for the forming ribbon-like CNC from the enzymolysis of cotton pulp fibers., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

In this work, the pulp fibers were enzymolyzed to prepare the nanosized cellulose (NC). The as-prepared samples were characterized by optical microscopy, electron microscopy, and Raman spectra. The experimental results indicated that enzymatic hydrolysis of pulp fibers could produce the spherical NC with a mean particle size of about 30nm, which had the excellent monodispersity and uniformity. When the concentration of complex enzymes was 20u/mL (cellulase: xylanase=9: 1), the yield of NC was 13.6%. The single cellulase was used, even if the enzyme concentration reached up to 200u/mL, only a mixture of strip and granular flocculation were obtained. The positive synergistic effect between xylanase and cellulase could be due to the enzymolysis of hemicellulose located on the cellulose microfibers to be favorable of cutting and splitting of the microfibers by the endoglucanase in cellulase., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

Zinc plays important roles in regulating physiological and pathological processes. Regrettably, mild to moderate zinc deficiency is common worldwide. Hair Zn(2+) concentration, which reflects a zinc storage status, is useful for tracking trends in zinc status within populations. In this work, we report BODIPY-based self-assembled nanoparticles (NPs) as fluorescence turn-on sensor for the selective sensing of Zn(2+) in human hair. The BODIPY monomers (BAN) self-assemble in aqueous medium to form nonfluorescent NPs. In the presence of Zn(2+) ions, the NPs selectively show an obvious turn-on fluorescence change. This selective response of the NPs allows the determination and quantification of Zn(2+) in human hair with a detection limit of 61.3nM. This study demonstrates that the small molecule self-assembled nanoparticle is a versatile and useful tool, and shows great potential for applications in sensing of important analytes in biological systems., (Copyright © 2016 Elsevier B.V. All rights reserved.)