The Key Laboratory of Advanced Textile Materials and Manufacturing Technology of Ministry of Education, College of Materials and Textile , Zhejiang Sci-Tech University , Hangzhou 310018 , China.
Department of Chemical Engineering, Waterloo Institute for Nanotechnology , University of Waterloo , 200 University Avenue West , Waterloo N2L 3G1 , Ontario , Canada.
ACS Appl Mater Interfaces. 2019 Dec 26;11(51):48192-48201. doi: 10.1021/acsami.9b13687. Epub 2019 Dec 13.
Spherical cellulose nanocrystals (SCNs) and rod-shaped cellulose nanocrystals (RCNs) were extracted from different cellulose materials. The two shape forms of cellulose nanocrystals (CNs) were designed with a combination of isothiocyanate (FITC), and both the obtained FITC-SCNs and FITC-RCNs exhibited high fluorescence brightness. The surfaces of SCNs and RCNs were subjected to a secondary imino group by a Schiff reaction and then covalently bonded to the isothiocyanate group of FITC through a secondary imino group to obtain fluorescent cellulose nanocrystals (FITC-CNs). The absolute ζ-potential and dispersion stability of FITC-CNs (FITC-SCNs and FITC-RCNs) were improved, which also promoted the increase in the fluorescence quantum yield. FITC-RCNs had a fluorescence quantum yield of 30.7%, and FITC-SCNs had a morphological advantage (better dispersion, etc.), resulting in a higher fluorescence quantum yield of 35.9%. Cell cytotoxicity experiments demonstrated that the process of FITC-CNs entering mouse osteoblasts (MC3T3) did not destroy the cell membrane, showing good biocompatibility. On the other hand, FITC-CNs with good dispersibility can significantly enhance poly(vinyl alcohol) (PVA) and poly(lactic acid) (PLA); their mechanical properties were improved (the highest sample reached to 243%) and their fluorescent properties were imparted. This study provides a simple surface functionalization method to produce high-luminance fluorescent materials for bioimaging, multifunctional nanoenhancement/dispersion marking, and anticounterfeiting materials.
球形纤维素纳米晶（SCNs）和棒状纤维素纳米晶（RCNs）是从不同的纤维素材料中提取的。这两种形态的纤维素纳米晶（CNs）通过异硫氰酸酯（FITC）组合设计，所得到的 FITC-SCNs 和 FITC-RCNs 都具有高荧光亮度。SCNs 和 RCNs 的表面通过席夫反应引入仲氨基基团，然后通过仲氨基基团与 FITC 的异硫氰酸酯基团共价键合，得到荧光纤维素纳米晶（FITC-CNs）。FITC-CNs（FITC-SCNs 和 FITC-RCNs）的绝对 ζ 电位和分散稳定性得到提高，这也促进了荧光量子产率的增加。FITC-RCNs 的荧光量子产率为 30.7%，而 FITC-SCNs 具有形态优势（更好的分散性等），导致荧光量子产率更高，达到 35.9%。细胞毒性实验表明，FITC-CNs 进入小鼠成骨细胞（MC3T3）的过程并未破坏细胞膜，表现出良好的生物相容性。另一方面，具有良好分散性的 FITC-CNs 可以显著增强聚乙烯醇（PVA）和聚乳酸（PLA）；其力学性能得到提高（最高可达 243%），并赋予其荧光性能。本研究提供了一种简单的表面功能化方法，用于制备用于生物成像、多功能纳米增强/分散标记和防伪材料的高亮度荧光材料。
