Fig. 1. Molecular structure and characterization of Chol–PEG–Cy5. (a) Molecular structure of Chol–PEG–Cy5. (b) 1H NMR spectrum of Chol–PEG–Cy5 in dimethyl sulfoxide-d6. The blue dotted circle indicates the characteristic proton peak of the Cy5 moiety. (c) MALDI-TOF mass spectrum of Chol–PEG–Cy5. (d) Surface tension curve of PBS solutions containing different concentrations of Chol–PEG–Cy5 as measured using an optical tensiometer.
