Intramolecular charge-transfer emission from conjugated polymer nanoparticles: the terminal group effect on electronic and optical properties

Tuning fluorescence properties and frontier orbital energy levels of hyperbranched conjugated polymer nanoparticles (HCPN-NMe) by the facile introduction of terminal N,N-dimethylaniline groups via an intramolecular charge transfer (ICT) process between the nanoparticle core and the terminal groups was demonstrated for the first time. Compared with the similar hyperbranched conjugated polymer nanoparticles with terminal benzene groups (HCPN-H), a large Stokes shift and remarkable fluorescence solvatochromism were observed for HCPN-NMe. Based on the environmental-sensitive ICT emission, HCPN-NMe can be used as a fluorescence sensor for the detection of water in THF with enhanced sensitivity.