Non-thermal or cold plasma create many reactive species and charged particles when brought into contact with plant extracts. The major constituents involve reactive oxygen species, reactive nitrogen species and plasma ultra-violets. These species can be used to synthesize biologically important nanoparticles. The current study addressed the effect of the green method-based preparation approach on the volumetric analysis of Zn nanoparticles. Under different operating conditions, the traditional thermal method and the microwave method as well as the plasma generation in dielectric barrier discharge reactor were adopted as a preparation approach in this study. The results generally show that the type of method used plays an important role in determining the size of the zinc particles produced. The traditional and microwave method stimulated the formation of clusters and agglomerates of Zn nanoparticles by effect of temperature parameter. As an example, it was noted that the lowest average diameter was obtained at 50 °C, which was 18.77 nm compared with 30.07, 23, 31, and 25.27 nm in diameter for particles generated with other temperatures of 30, 60, 70, and 80 °C respectively. These formations can occur at relatively low temperature at the expense of the formation of irregular particles. However, the weights of pre-prepared Petroselinum crispum seeds, and the ratio of the extract of P. crispum seeds to the salt, are factors that may play an important role in determining the size of the Zn nanoparticles. The current study has also shown that the highest percentage of generated nanoparticles was obtained with the cold plasma method under moderate operating conditions with the advantage of the economic factor. In addition, the Zn nanoparticles synthesized by cold plasma method in 10 min in all concentrations showed more inhibition effect as antifungal against Candida albicans.
