pH-Responsive fluorescent supramolecular nanoparticles based on tetraphenylethylene-labelled chitosan and a six-fold carboxylated tribenzotriquinacene

Nan Yang; Yi-Yan Zhu; Wei-Xiu Lin; Yi-Long Lu; Wen-Rong Xu

doi:10.3762/bjoc.19.45

pH-Responsive fluorescent supramolecular nanoparticles based on tetraphenylethylene-labelled chitosan and a six-fold carboxylated tribenzotriquinacene

Beilstein J Org Chem. 2023 May 8:19:635-645. doi: 10.3762/bjoc.19.45. eCollection 2023.

Authors

Nan Yang¹, Yi-Yan Zhu¹, Wei-Xiu Lin¹, Yi-Long Lu¹, Wen-Rong Xu¹

Affiliation

¹ Key Laboratory of Advanced Materials of Tropical Island Resources of Ministry of Education, Hainan Provincial Key Laboratory of Fine Chemistry, School of Chemical Engineering and Technology, School of Science, Hainan University, Haikou 570228, PR China.

Abstract

We synthesized a new tetraphenylethylene-modified chitosan bioconjugate, CS-TPE, that shows the aggregation-induced emission effect. It can self-assemble into fluorescent polymeric nanoparticles in an aqueous solution at pH 5.3 either alone or with the water-soluble bowl-shaped six-fold carboxylated tribenzotriquinacene derivative TBTQ-C₆ via host-guest binding. The spherical nanoparticles formed by CS-TPE amphiphiles or TBTQ-C₆/CS-TPE supra-amphiphiles disintegrated under alkaline stimulation at pH 10.4 and the dispersion of the aggregates after the collapse in the presence of TBTQ-C₆ was greatly improved. In addition, the fluorescence of CS-TPE was significantly enhanced by introducing TBTQ-C₆, and remained relatively stable with variations in pH for both CS-TPE and TBTQ-C₆/CS-TPE. Such pH-responsive supramolecular spherical nanoparticles with stable fluorescence emission based on CS-TPE or TBTQ-C₆/CS-TPE may find applications in various fields, including the development of visual oral drug delivery systems.

Keywords: chitosan; nanoparticle; tetraphenylethylene; tribenzotriquinacene.

Grants and funding

We thank the National Natural Science Foundation of China (No. 22061015) and the Hainan High-level Talents Program (No. 2019RC156) for the financial support.