Future Prospects of Phytosynthesized Transition Metal Nanoparticles as Novel Functional Agents for Textiles - Advanced Materials for Agriculture, Food and Environmental Safety - page 278

PLANT EXTRACTS

Alkaloids Flavonoids Enzymes Proteins Polysaccharides Saponins Sterols Tannins Terpenoids

BIOREDUCING AGENTS

M + M 0

REDUCTION

Metal ion

GROWTH

M 0

M 0
M 0

M 0 M 0 M 0

M 0
M 0

M 0

M 0

M 0

M 0 M 0 M 0

M 0

M 0 STABILIZATION M 0 M 0

M 0

M 0

Metal nanoparticles

Figure 10.1 Synthesis of nanoparticles using bioconstituents from plants.

antioxidants, proteins/enzymes, amino acids, polysaccharides, alkaloids,
alcoholic compounds, vitamins and other water-soluble heterocyclic com-
ponents in plants are mainly responsible for the production and stabiliza-
tion of the nanoparticles (Figure 10.1) [9, 13].
For example, Zhan and coworkers [114] verii ed by FTIR the pres-
ence of functional groups like C=O and C-O groups in the leaf extract
of Cacumen platycladi and their role in the synthesis of Au-Pd bimetallic
nanoparticles (~7 nm). Likewise, MubarakAli et al. [60] showed that the
leaf extract of menthol is very good bioreductant for the synthesis of silver
and gold nanoparticles.
Recently, palm oil mill el uent was used by Gan et al. [115] as a reducing
agent for the synthesis of spherical gold nanoparticles with an average size
of 18.75 ± 5.96 nm. h e FTIR analysis of palm oil mill el uent before and
at er the gold nanoparticle formation showed the disappearance of N-H or
C=O stretching vibrations bands at 2351cm -1 . h is fact can be attributed to
the presence of proteins or l avonoids that contain abundant C=O or N-H
groups, which are presumed to act as reducing and capping agents for the
gold nanoparticles.
Jagtap and Bapat [116] reported the use of Artocarpus heterophyllus seed
powder extract (ASPE) as a reducing agent for the synthesis of spherical-
shaped silver nanoparticles. h eir study indicated the involvement of
amides, carboxyl, amino groups and amino acid residues present in ASPE
extract for the synthesis of silver nanoparticles. Similarly, Bankar and col-
leagues [46] proposed the role of carboxyl, amine and hydroxyl groups in
the formation of palladium nanoparticles using peel extract of banana fruit.