The study compared the antibacterial activity of synthesized ZnO nanoparticles(NPs)from fresh leaf and fresh stem bark aqueous extracts of Carica papaya against five selected microbes:Staphylococcus aureus,(Gram posit...The study compared the antibacterial activity of synthesized ZnO nanoparticles(NPs)from fresh leaf and fresh stem bark aqueous extracts of Carica papaya against five selected microbes:Staphylococcus aureus,(Gram positive(+ve)),Escherichia coli(Gram negative(-ve)),Acinetobacter baumanni(Gram-ve),Exiguobacterium aquaticum(Gram+ve),and Klebsielia pneumonia(Gram+ve).The morphological features of the biosynthesized ZnO NPs were analyzed using transmission electron microscope(TEM)and scanning electron microscope(SEM);the Fourier-transform infrared spectrometer(FTIR)technique was used to observe the surface functional groups.The experimental results indicated that ZnO NPs were successfully synthesized using modified hydrothermal technique,which showed agglomerated flake-like or petal-like shapes with the organic extract surrounding the formed particles.The average particle size of the synthesized ZnO nanoparticles determined by SEM ranged between 54-97 nm with the width and length of the petal-like structures been 30 nm and 62 nm respectively.The average ZnO NPs from fresh stem bark extract of Carica papaya with higher concentrations(100-1000 ppm)demonstrated a higher antibacterial activity than the fresh leaf extracts.On the other hand,ZnO NPs from fresh leaf extracts of lower concentrations(25-50 ppm)rather showed a suitable result than the fresh stem bark.In general,ZnO NPs showed a positive antibacterial result towards the selected microbes.This shows that,the synthesized ZnO NP can be a substitute to chemical methods.展开更多
基金supported by Universiti Malaysia Sarawak,Tun Openg Chair,with Research Grant Code:F07/TOC/1738/2018.
文摘The study compared the antibacterial activity of synthesized ZnO nanoparticles(NPs)from fresh leaf and fresh stem bark aqueous extracts of Carica papaya against five selected microbes:Staphylococcus aureus,(Gram positive(+ve)),Escherichia coli(Gram negative(-ve)),Acinetobacter baumanni(Gram-ve),Exiguobacterium aquaticum(Gram+ve),and Klebsielia pneumonia(Gram+ve).The morphological features of the biosynthesized ZnO NPs were analyzed using transmission electron microscope(TEM)and scanning electron microscope(SEM);the Fourier-transform infrared spectrometer(FTIR)technique was used to observe the surface functional groups.The experimental results indicated that ZnO NPs were successfully synthesized using modified hydrothermal technique,which showed agglomerated flake-like or petal-like shapes with the organic extract surrounding the formed particles.The average particle size of the synthesized ZnO nanoparticles determined by SEM ranged between 54-97 nm with the width and length of the petal-like structures been 30 nm and 62 nm respectively.The average ZnO NPs from fresh stem bark extract of Carica papaya with higher concentrations(100-1000 ppm)demonstrated a higher antibacterial activity than the fresh leaf extracts.On the other hand,ZnO NPs from fresh leaf extracts of lower concentrations(25-50 ppm)rather showed a suitable result than the fresh stem bark.In general,ZnO NPs showed a positive antibacterial result towards the selected microbes.This shows that,the synthesized ZnO NP can be a substitute to chemical methods.
