AFM analysis of C ₆₀ and a poly(amido amine) dendrimer-C ₆₀ nanoconjugate

Atomic force microscopy (AFM) was used to study the nanoscopic structure and topography of buck-minsterfullerene (C ₆₀) and a conjugate of C ₆₀ with generation four, amine-terminated, poly(amido amine) dendrimer (PAMAM-G4). The conjugate contains a PAMAM-G4 core and C ₆₀ shell formed by reacting PAMAM-G4 with an excess of C ₆₀. ¹ Fractal patterns of C ₆₀ were observed in nanoscopic AFM images when solutions of different concentrations of C ₆₀ in pyridine or toluene were dried at room temperature. In contrast, no fractal patterns were detected in the AFM images of the dendrimer-C ₆₀ nanoconjugate, prepared from pyridine solution in a similar manner. Thus, the C ₆₀-shell alone is not sufficient to impart the same fractal patterns on the conjugate.