文献类型：期刊文献

英文题名：Fluorescent cellulose nanocrystals with responsiveness to solvent polarity and ionic strength

作者：Wu, Weibing[1] Song, Ruyuan[1] Xu, Zhaoyang[2] Jing, Yi[1] Dai, Hongqi[1] Fang, Guigan[3]

第一作者：Wu, Weibing

通信作者：Dai, HQ[1];Xu, ZY[2]

机构：[1]Nanjing Forestry Univ, Jiangsu Coinnovat Ctr Efficient Proc & Utilizat F, Nanjing 210037, Jiangsu, Peoples R China;[2]Nanjing Forestry Univ, Coll Mat Sci & Engn, Nanjing 210037, Jiangsu, Peoples R China;[3]Chinese Acad Forestry, Inst Chem Ind Forestry Prod, Nanjing 210042, Jiangsu, Peoples R China

年份：2018

卷号：275

起止页码：490-498

外文期刊名：SENSORS AND ACTUATORS B-CHEMICAL

收录：;EI(收录号：20184005896812);Scopus(收录号：2-s2.0-85054050010);WOS:【SCI-EXPANDED(收录号:WOS:000445264000060)】；

基金：The support of this work by Natural Science Foundation of Jiangsu Province (BK20171450), the National Key Basic Research Program (2017YFD0601005), Priority Academic Program Development of Jiangsu Higher Education Institutions (PAPD), and National Natural Science Foundation of China (31370583, 31770607) is gratefully acknowledged.

语种：英文

外文关键词：Cellulose nanocrystals; Fluorescence; Ionic strength; Solvent permittivity; Double layer

摘要：Fluorescent and stimuli-responsive cellulose nanocrystals (CNC) were prepared via covalent conjugation of a 1, 8-naphthalimide dye onto TEMPO-oxided CNC. The structural and morphological integrity of CNC were essentially not affected by the functionalizaiton, in spite of their relatively high dye content of 0.1 +/- 0.01 mmol g(-1). The dye-labeled CNC show much higher fluorescence sensitivity to solvent polarity and ion concentration compared to pure dye. The fluorescence emission of dye-labeled CNC is greatly enhanced when reducing solvent permittivity or increasing ionic strength. The magnified fluorescence responsiveness is attributed to the effect of aggregation-enhanced emission (AEE) based on the sensitive colloidal stability of CNC to medium conditions. Under high ionic strength and low solvent permittivity, the compressed double layers of CNC lead to space restriction and steric hindrance of dye groups, which limit the process of nonradiative transition. The aggregation of CNC triggered by the change of ion concentration was supported by dynamic light scattering (DLS) particle sizes and Zeta potential values. Owing to the special AEE effect, the fluorescent CNC are promising sensing nanomaterials for wide applications.