Novel amphiphilic π-conjugated polymer nanoparticles tailored to efficiently absorb in the near-infrared II (NIR-II) region of the electromagnetic spectrum (>1000 nm) are presented. To achieve this, it is statistically introduced triethylene glycol substituted bithiophene moieties in various contents into a polymer backbone consisting of alternating thiophene and [1,2,5]thiadiazolo[3,4-g]quinoxaline. Through systematic modifications of monomer ratios, four amphiphilic conjugated polymers …