Near Infrared Emitting Semiconductor Polymer Dots for Bioimaging and Sensing

Semiconducting polymer dots (Pdots) are rapidly becoming one of the most studied nanoparticles in fluorescence bioimaging and sensing. Their small size, high brightness, and resistance to photobleaching make them one of the most attractive fluorophores for fluorescence imaging and sensing applications. This paper highlights our recent advances in fluorescence bioimaging and sensing with nanoscale luminescent Pdots, specifically the use of organic dyes as dopant molecules to modify the optical properties of Pdots to enable deep red and near infrared fluorescence bioimaging applications and to impart sensitivity of dye doped Pdots towards selected analytes. Building on our earlier work, we report the formation of secondary antibody-conjugated Pdots and provide Cryo-TEM evidence for their formation. We demonstrate the selective targeting of the antibody-conjugated Pdots to FLAG-tagged FLS2 membrane receptors in genetically engineered plant leaf cells. We also report the formation of a new class of luminescent Pdots with emission wavelengths of around 1000 nm. Finally, we demonstrate the formation and utility of oxygen sensing Pdots in aqueous media.

Automated summary

Semiconducting polymer dots (Pdots) are widely studied nanoparticles in fluorescence bioimaging and sensing due to their small size, high brightness, and resistance to photobleaching. This paper highlights recent advances in using organic dyes as dopants to modify the optical properties of Pdots for deep red and near infrared fluorescence bioimaging, as well as for imparting sensitivity towards selected analytes. Additionally, the formation of secondary antibody-conjugated Pdots and their selective targeting to specific membrane receptors in plant leaf cells, as well as the development of a new class of luminescent Pdots with emission wavelengths around 1000 nm, are reported.