Figure 6.

(A) Neat carbon nanodots (C-dots) did not display any catalytic activity, as evidenced by the lack of green color in (Ai); while native cytochrome c (cyt c) was found to exhibit weak peroxidase activity (Aii); When C-dots were combined with cyt c, the peroxidase activity was dramatically enhanced, indicated by the rapid formation of the oxidized form of ABTS (i.e., appearance of intense green color), as shown in (Aiii); (B) Different orientations of the electrostatic calculations performed on cyt c show that a majority of the protein surface is positively charged (blue areas), with the bulk of the positive charge residing in the vicinity of the heme group. Reproduced from [54].