Thümmler, J. F., et al. Macromol. Rapid. Commun., 2022, DOI:https://doi.org/10.1002/marc.202200618
Controlling the internal structures of single-chain nanoparticles (SCNPs) is an important factor for their targeted chemical design and synthesis, especially in view of nanosized compartments presenting different local environments as a main feature to control functionality. We here design SCNPs (sized 6 – 12 nm) bearing near-infrared fluorescent dyes embedded in hydrophobic compartments for use as contrast agents in pump–probe photoacoustic (PA) imaging. SCNPs with the dye molecules accumulate at the core and show a nonlinear PA response as a function of pulse energy—a property that can be exploited as a contrast mechanism in molecular PA tomography.