It indicated that no reduction from Ag+ to Ag0 occurred in Fig. 1(1).
The location of absorption peaks was about 415 nm [Fig. 1(2) and (3)],
evincing that AgNPs formed. Although the size and morphology of
AgPNs capped by ALE were different in overgrown aloe and tender one,
it was obvious that ALE had both protective and reductive effects. We
hypothesized that ALEwas inherently rich in polymers such as anthraquinone
and polysaccharose used as cap in the synthesis of AgNPs by T.H.
Emaga [28]. Interestingly, overgrown aloe hadmore anthraquinone compounds.
Furthermore, mesophyll tissue, containing many polysaccharose
and other physiologically-active components, in overgrown aloe was
much more than that in tender one so that overgrown aloe was more
protective and reductive in the synthesis of AgNPs.