*4.3.5 Novel concepts*

The novel concept could be traced out where different strategies can be applied to nanoparticle synthesis. It is reported in [14] paper that a specific type of wound stress has been applied to the plant leaf sample of the medicinal plant *Passiflora foetida* (leaf cut 2 cm in diameter and used to collect diffusate) and that secondary metabolite-induced stress has been extracted (see **Figure 5**). In this context, a stressed-induced plant extract is used, which contains stress-induced secondary metabolites and phytochemicals that reduce silver ion and act as a capping agent responsible for the synthesis of silver nanoparticles. The use of such stress-induced pool extracts may be considered for the formulation of silver nanoparticles [14].


**105**

*Phytonanofabrication: Methodology and Factors Affecting Biosynthesis of Nanoparticles*

*DOI: http://dx.doi.org/10.5772/intechopen.90918*

**5. Factors affecting biosynthesis of nanoparticles**

nanoparticle synthesis.

**Figure 5.**

**5.1 Reaction temperature**

*using leaf disc under sunlight [14].*

**5.2 Volume of leaf extract**

Manufacturing nanoparticles is a very critical process where the environmental factor is temperature and pressure; light intensity plays an important role in the synthesis of nanoparticles. Parameters such as sample leaf extract concentration, AgNO3 concentration, reaction temperature, reaction time, pH reaction and different light reactions play a key role in the creation of silver nanoparticles of varying size, shape and dimension. Similarly, the light conditions such as sun light, blue light, red light, bulb light, tube light and in dark devoid of light effects are examined for nanoparticle biosynthesis. Several parameters that play a crucial role in the synthesis of the particular nanoparticles required have been addressed briefly. Such parameters are modified in order to produce the desired size of nanoparticles for the study of specific activity. Temperature is one of the most important parameters for

*Leaf disc preparation using test tube for applying wound stress to* P. foetida *and synthesis of silver nanoparticles* 

Temperature has a specific effect on the process of synthesis of silver nanoparticles. Usually, the reaction is performed at room temperature, which takes a long time to complete, but can be accelerated by increasing the temperature of the reaction mixture. The temperature can be adjusted to between 30 and 100°C. Increased

homogeneous nucleation of silver nuclei, enabling the development of small size silver nanoparticles [18]. It has been found that as the temperature of the reaction mixture increases the rate of nanoparticle synthesis decreases, as well as the stability increases. In addition, silver nanoparticles synthesized at higher temperatures have small nanoparticle sizes. Another parameter that is important during silver

The quantity of leaf extract, that is, the volume of leaf extract, also affects the processing of nanoparticles and affects the time required for silver nanoparticle formation. Because leaf extracts are a major part of the reduction of silver ion, their volume up to a certain quantity is efficient in the formation of silver nanoparticles. Generally, the 1, 5, 10, 15, 20 and 100 ml leaf extract could be checked for effect. It is advised to use 1, 2, 3, 4 and 5 ml, since less volume is required for nanoscale particle synthesis. The average particle size of the synthesized silver nanoparticles is highly influenced by the concentration of leaf extract that the contents (phenol, polyphenols, polysaccharides, tannins and anthocyanins) contributes significantly

ions and subsequent

reaction temperature led to a rapid reduction in the rate of Ag+

nanoparticle synthesis is volume of leaf extract.
