Figure 4From: Delivery of small interfering RNAs in human cervical cancer cells by polyethylenimine-functionalized carbon nanotubesFTIR spectra of pristine and PEI-functionalized carbon nanotubes. Pristine and PEI-functionalized carbon nanotubes were analyzed by a PerkinElmer Spectrum 100 FTIR spectrometer, and the spectra were compared with that of pure PEI.Back to article page