AFM Analysis of C₆₀ and a Poly(amido amine) Dendrimer-C₆₀ Nanoconjugate

Atomic force microscopy (AFM) was used to study the nanoscopic structure and topography of buckminsterfullerene (C₆₀ and a conjugate of C₆₀ with generation four, amine-terminated, poly(amido amine) dendrimer (PAMAM-G4). The conjugate contains a PAMAM-G4 core and C₆₀ shell formed by reacting PAMAM-G4 with an excess of C₆₀· Fractal patterns of C₆₀ were observed in nanoscopic AFM images when solutions of different concentrations of C₆₀ in pyridine or toluene were dried at room temperature. In contrast, no fractal patterns were detected in the AFM images of the dendrimer-C₆₀ nanoconjugate, prepared from pyridine solution in a similar manner. Thus, the C₆₀-shell alone is not sufficient to impart the same fractal patterns on the conjugate.