Structural And Dosage Dependence Of Electron Transfer From Conjugated Polymer Nanoparticles

Conjugated polymer nanoparticles (CPNs or Pdots) have become popular fluorophores for a variety of fluorescence imaging applications due to their brightness, photostability, and aqueous compatibility. Recently, their ability to generate charged species has begun to be exploited in applications ranging from photocatalysis to photovoltaic cells. Upon excitation, CPNs can eject an electron via photoinduced electron transfer (PET) to oxygen or other acceptors. The competition between fluorescence and PET is undesirable in redox-based applications. However, CPNs are capable of the simultaneous generation and detection of reactive oxygen species, expanding their use in photodynamic therapy (PDT). We seek to determine the dependence of PET on conjugated polymer structure and irradiation dosage. We will present studies of PET and fluorescent superoxide sensing in the most widely-used CPNs. These results will ultimately aid in the selection of polymers and irradiation conditions for PDT applications