One-step hydrothermal synthesis of a flexible nanopaper-based Fe3+ sensor using carbon quantum dot grafted cellulose nanofibrils

摘要

Photoluminescent flexible nanopaper-based Fe3+ sensors were fabricated by carbon quantum dot (CQD) grafted oxidized cellulose nanofibrils (OCNF). Transparent and tunable luminescent CQD-OCNF nanopapers were facilely synthesized from citric acid, ethanediamine and an OCNF suspension using a one-pot hydrothermal method without catalysts. The morphology and chemical structures of the CQD-OCNF nanopapers were investigated by TEM, SEM, XRD, FT-IR spectroscopy, XPS and CP/MAS C-13 NMR spectroscopy. The carboxyl groups of OCNF were covalently bonded to the amino groups of the newly-formed CQDs. The resultant CQD-OCNF nanopapers presented high transparency in bright field imaging and strong blue emission under ultraviolet excitation. The CQD-OCNF nanopaper was used as a highly sensitive and selective fluorescent sensor for Fe3+ ions. This study provides a facile and effective method for fabricating luminescent CQD-OCNF nanopapers with high selectivity for the detection of Fe3+. Graphic abstract