Green synthesis of metal nanoparticles and study their anti-pathogenic properties against pathogens effect on plants and animals

Abstract

According to an estimate, 30% to 40%, of global fruit are wasted, leading to post harvest losses and contributing to economic losses ranging from $10 to $100 billion worldwide. Among, all fruits the discarded portion of oranges is around 20%. A novel and value addition approach to utilize the orange peels is in nanoscience. In the present study, a synthesis approach was conducted to prepare the metallic nanoparticles (copper and silver); by utilizing food waste (Citrus plant peels) as bioactive reductants. In addition, the Citrus sinensis extracts showed the reducing activity against metallic salts copper chloride and silver nitrate to form Cu-NPs (copper nanoparticles) and Ag-NPs (Silver nanoparticles). The in vitro potential of both types of prepared nanoparticles was examined against plant pathogenic bacteria Erwinia carotovora (Pectobacterium carotovorum) and pathogens effect on human health Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). Moreover, the in vivo antagonistic potential of both types of prepared nanoparticles was examined by their interaction with against plant (potato slices). Furthermore, additional antipathogenic (antiviral and antifungal) properties were also examined. The statistical analysis was done to explain the level of significance and antipathogenic effectiveness among synthesized Ag-NPs and Cu-NPs. The surface morphology, elemental description and size of particles were analyzed by scanning electron microscopy, transmission electron microscopy, energy-dispersive spectroscopy and zeta sizer (in addition polydispersity index and zeta potential). The justification for the preparation of particles was done by UV-Vis Spectroscopy (excitation peaks at 339 nm for copper and 415 nm for silver) and crystalline nature was observed by X-ray diffraction. Hence, the prepared particles are quite effective against soft rot pathogens in plants and can also be used effectively in some other multifunctional applications such as bioactive sport wear, surgical gowns, bioactive bandages and wrist or knee compression bandages, etc.

Keywords: Antipathogens; Bandages; Eco-friendly; Green synthesis; Nanoparticles; Plant pathogens.

Figure 1

(a) Citrus sinensis peel flakes, (b) extraction through reflux, (c) CuCl₂·2H₂O solution, (d) greenish black solution of Cu-NPs, (e) calcinated obtained Cu-NPs, (f) AgNO₃ solution, (g) greenish grey solution of silver nanoparticles, (h) calcinated obtained Ag-NPs.

Figure 2

The process of coating the nanoparticles over the (a) potato slices, (b) fabric structure.

Figure 3

The particle size distribution of (a) Cu-NPs and (b) Ag-NPs.

Figure 4

(a–c) TEM analysis, SEM analysis and EDX spectra of silver particles (d–f) TEM analysis, SEM analysis and EDX spectra of copper particles.

Figure 5

(a) UV–Vis Spectrum of the orange peels extract, synthesized copper and silver nanoparticles, (b) XRD peaks of silver nanoparticles and (c) XRD pattern of Cu-NPs.

Figure 6

The FT-IR spectra of orange peels extract, copper particles and silver particles coated fabrics.

Figure 7

Growth inhibitions in response to (a) Cu-NPs and (b) Ag-NPs against plant pathogens (P. carotovorum) and (c) graphical representation of zone of inhibition values for samples coated with silver and copper particles.

Figure 8

Potato slices with zone of infection caused by P. carotovorum (a) uncoated sample, (b) coated with copper particles and (c) coated with silver particles and (d) bar graphs showing the values of their respective zone of infections.

Figure 9

Antibacterial activity in terms of log CFU/ml (left) and percentage reduction (right) of fabrics treated with silver and copper nanoparticles and untreated cotton fabric.

Figure 10

Images of concentration of bacterial growth for the (a,b) copper particles, (c,d) for silver particles and (e,f) for untreated fabrics.

Figure 11

Inhibition zones (a) against S. aureus, (b) E. coli., (c) graphical representation of Zone of inhibition around all samples.

Figure 12

Images shows fungus growth against (a) silver particles coated samples, (b) against copper particles coated samples, (c) raw cotton and (d) percentage reduction in fungal spore germination for each fabric specimen.

Figure 13

Reduction in viral infectivity titer (a) and percentage adsorption (b) calculated from viral infectivity at a contact time of 0 and 60 min.