Determination of superoxide radicals in aqueous solutions of C60 and its derivatives

The aqueous solutions of C-60 and C-60 NCH2CONH2 (N-acetamide 1,2-dihydro-1, 2-aza-fullerene [C-60]) were prepared by the polyvinylpyrrolidone method Using lucigenin as the photosensitive probe for the superoxide radicals, the superoxide radicals in the solution of CM,and its five derivatives (including C60NCH2CONH2, C-60 (OH)(n) and three C-60/70 acrylic acid copolymers) were determined under both irradiation and non-irradiation by photon calculator. The effect of C-60 (OH)(n) on the superoxide radicals was also studied. The results show that the superoxide radicals can be generated only in the C-60 solution under irradiation, while C-60 (OH)(n) has the activity of reducing the superoxide radicals in aqueous solution, suggesting that the superoxide radicals are involved in the photosensitive reaction of C-60, but not in those of its derivatives.