Water-Soluble Semiconducting Nanoparticles for Imaging

Water-soluble semiconducting nanoparticles are prepared from individually collapsed and crosslinked ABA triblock copolymers and are further modified to carry imaging units and allyl functionalities for postmodification. Ethylene oxide modified polyfluorene forms the center block (B) and is transformed into a telechelic macroinitator. In a nitroxide mediated living free radical polymerization, polyacrylate blocks (A) are grown to give the ABA triblock copolymer. Low-temperature benzocyclobutene crosslinking groups are attached to collapse and site-isolate the center block (A). The nanoparticles were further modified by pegylation to enhance the solubility and by catechol groups to provide complexing sites for magnetic resonance imaging (MRI) reagents such as gadolinium. The reported materials are water-soluble and encompassing fluorescence and MRI to become biocompatible "organic quantum dots" with the possibility to interact actively with biological entities.