ZnO/Ag Nanocomposites with Enhanced Antimicrobial Activity
, Loredana Scalschi 2, Begonya Vicedo 2, Maxim Guc 3, VÃctor Izquierdo-Roca 3, Samuel Porcar 1, Diego Fraga 1 and Juan B. Carda 1
Round 1
Reviewer 1 Report
In this work author synthesized ZnO/Ag nanocomposites by facile chemical route to evaluate the antimicrobial activity. The nanocomposites were analyzed using XRD, SEM, STEM, UV-Vis spectroscopy, and Raman spectroscopy. The study presented in this research is sound, and the results produced are interesting. The paper is sufficiently novel to meet the requirements of the Applied Sciences journal. But a major revision is required, especially for the improvement of the English language. And after responding to the following remarks and revising the paper, the manuscript may be considered for publication in the Applied Sciences journal.
- The novelty of the work is missing in the introduction. Authors are suggested to include a separate paragraph by discussing the novelty and importance of the present work.
- The quality of Figure 8 is low, please increase the quality. If necessary, redraw.
- Change the font text of Figure 7 from gray to black to make it more visible.
- The font size inside and/or outside the Figures 1, 4, 5, and 6, is not clearly visible, increase the font size to make it visible.
- Authors are suggested to use more references from recent past, and recommend to cite following all references in the introduction section: 10.1016/j.apsadv.2022.100227; 10.1016/j.apmt.2021.101104; 10.1021/acsabm.2c00002.
- The conclusion is too long to follow. In the Conclusion section, state the most important outcome of your work. Do not simply summarize the points already made in the body — instead, interpret your findings at a higher level of abstraction. Show whether, or to what extent, you have succeeded in addressing the need stated in the Introduction.
- Also, it's better to change the name of section 4 from "Conclusion" to "Summary”.
- The similarity is 34% which is not acceptable. Please check the attached Turnitin Plagiarism Report, and reduce similarity.
- English as their first language needs to read and edit the entire manuscript to improve readability before resubmission for consideration of publication in this journal. Also, a major revision is suggested to improve the English language.
- Also, check the typos throughout the manuscript during revision submission.
Comments for author File: 
Comments.pdf
Author Response
1. The novelty of the work is missing in the introduction. Authors are suggested to include a separate paragraph by discussing the novelty and importance of the present work.
Response: Thank you very much for the nice suggestions. The new separate paragraph is included in the revised manuscript (page 3, Line 80-84).
2. The quality of Figure 8 is low, please increase the quality. If necessary, redraw.
Response: Thank you very much for the nice suggestions. The Figure 8 has been replaced for another with more quality. (page 15).
3. Change the font text of Figure 7 from gray to black to make it more visible.
Response: Thank you very much for the nice suggestions. This point is done. (Page 14).
4. The font size inside and/or outside the Figures 1, 4, 5, and 6, is not clearly visible, increase the font size to make it visible.
Response: Thank you very much for the nice suggestions. This point is done.(Page 7,11,12 and 13)
5. Authors are suggested to use more references from recent past, and recommend to cite following all references in the introduction section: 10.1016/j.apsadv.2022.100227; 10.1016/j.apmt.2021.101104; 10.1021/acsabm.2c00002.
Response: Thank you very much for the nice suggestions. Some of references has been added in the introduction (Reference 7 and 8)
6. The conclusion is too long to follow. In the Conclusion section, state the most important outcome of your work. Do not simply summarize the points already made in the body — instead, interpret your findings at a higher level of abstraction. Show whether, or to what extent, you have succeeded in addressing the need stated in the Introduction.
Response: Thank you very much for the nice suggestions. The summary has been changed for a short version. (Page 17, Lines 336-353)
7. Also, it's better to change the name of section 4 from "Conclusion" to "Summary”.
Response: This point is done.
8. The similarity is 34% which is not acceptable. Please check the attached Turnitin Plagiarism Report, and reduce similarity.
Response: Thank you very much for the nice suggestions. With the changes applied in the manuscript the percetage of similarity has been decreased.
9. English as their first language needs to read and edit the entire manuscript to improve readability before resubmission for consideration of publication in this journal. Also, a major revision is suggested to improve the English language.
Response: Thank you very much for the nice suggestions. The english has been improved.
10. Also, check the typos throughout the manuscript during revision submission
Response: Thank you very much for the nice suggestions. The typos has been checked.
Author Response File: 
Author Response.docx
Reviewer 2 Report
The manuscript “ZnO/Ag nanocomposites with enhanced antimicrobial activity” deals with the production of antimicrobial nanocomposites thanks to the presence of silver nanoparticles. Te work is interesting and well organized. Moreover, several analyses were performed on the samples. However, in the present form, the work is more similar to a scientific report than to a scientific paper. For this reason, some revisions are required, as follows:
- Abstract. Specify the production method used for the nanocomposites. Add quantitative results.
- The state of the art on the production of polymeric supports used to host silver nanoparticles can be enlarged, adding other works that describe the effect of the porous matrix on the antibacterial activity of silver; for this purpose, see for instance these works: Baldino et al., Journal of Chemical Technology and Biotechnology, 2019, 94(1), pp. 98–108; Zhao et al., RSC Advances, 2022, 12(13), 8256-8262; Huang et al., Polymers, 2022, 14(5), 976; etc..
- R&D. The description and the discussion of the obtained results can be enlarged, performing a comparison with the previous literature to underline the relevance of the present findings. Moreover, Figure 8 should be enlarged, since it is difficult to be observed.
- Correct typos.
- Improve English.
Author Response
1. Abstract. Specify the production method used for the nanocomposites. Add quantitative results
Response: Thank you very much for the nice suggestions. The abstract has been change and the production method use has been introuduced. (Page 1, Line 13-17)
2. The state of the art on the production of polymeric supports used to host silver nanoparticles can be enlarged, adding other works that describe the effect of the porous matrix on the antibacterial activity of silver; for this purpose, see for instance these works: Baldino et al., Journal of Chemical Technology and Biotechnology, 2019, 94(1), pp. 98–108; Zhao et al., RSC Advances, 2022, 12(13), 8256-8262; Huang et al., Polymers, 2022, 14(5), 976; etc.
Response: Thank you very much for the nice suggestions. Some of the references has been added and the state of the art has been changed. (Page 1. Line 41-43)
3. R&D. The description and the discussion of the obtained results can be enlarged, performing a comparison with the previous literature to underline the relevance of the present findings. Moreover, Figure 8 should be enlarged, since it is difficult to be observed.
Response: Thank you very much for the nice suggestions. Figure 8 has been changed and a comparison with previous literature has been adeed (Page 15, Line 293-296) and (Page 16, Line 315-323)
4. Correct typos
Response: It's done
5. Improve English
Reponse: It's done
Author Response File: Author Response.docx
Reviewer 3 Report
The manuscript entitled “ZnO/Ag nanocomposites with enhanced antimicrobial activity” reported the synthesis of ZnO/Ag nanocomposites with tunable Ag concentration by a sol-gel method for the inhibition of bacterial growth. The as-synthesized nanocomposites were characterized carefully by XRD, SEM, EDX, UV-vis spectroscopy, and Raman spectroscopy. ZnO and ZnO/Ag nanocomposites showed better bactericidal effect when compared to controls without using any nanoparticles. The result overall is interesting, and the manuscript reads well. The study is complete, and the characterization is thorough. Therefore, I would recommend the manuscript to publish after the following points are addressed satisfactorily.
- There have been many studies on the antimicrobial or antibacterial activity of ZnO/Ag nanocomposites in the literature. Therefore, it would be better to review previous progress and provide more discussions to differentiate this work from the previous ones.
- It would be better to provide size distribution histogram for SEM images of different ZnO/Ag nanocomposites.
- It would be better to evaluate the actual Ag concentration in the samples.
- The authors stated that a reduction in bacterial growth was observed from 3h of inoculation. However, there is no 3h data.
- P-values for the significant difference need to be provided.
- Figure 3, which sample was used for the characterization? Information should be provided.
- Although Ag did not seem to contribute much to the antibacterial activity, it would still be beneficial to discuss the reasons. The authors claimed that it was possibly due to Ag agglomeration, however, no data was provided to support the hypothesis. Would the size of ZnO (Figure 2 shows samples have different sizes) have any effect? More discussions are needed. Referring to previous studies would also be helpful.
Author Response
1. There have been many studies on the antimicrobial or antibacterial activity of ZnO/Ag nanocomposites in the literature. Therefore, it would be better to review previous progress and provide more discussions to differentiate this work from the previous ones.
Response: Thank you very much for the nice suggestions. A new discussion of the data and state of art have been introduced, providing a specific biography in the introduction and in the discussion. (Page 3, Lines 80-84), (Page 15, 293-296) and (Page 16, 315-323).
2. It would be better to provide size distribution histogram for SEM images of different ZnO/Ag nanocomposites.
Response: Thank you very much for the nice suggestions. I believe that with the SEM scale, the particle size of nanocomposites can be correctly evaluated.
3. It would be better to evaluate the actual Ag concentration in the samples.
Response: The evaluation of the silver concentration in a quantitative way can only be carried out by dissolving the nanocomposites in acid and doing a liquid chromatography, something that is very complicated since the equipment is not available. I think that with the intensity of the XRD peaks and the STEM, a lot of information is given.
4. The authors stated that a reduction in bacterial growth was observed from 3h of inoculation. However, there is no 3h data.
Response: Thank you very much for the nice suggestions. The data has been changed for 6h.
5. P-values for the significant difference need to be provided.
Response: Thank you very much for the nice suggestions. The p value is 0.05, since an ANOVA analysis of variance was applied using Fisher's least significant differences test at the 95% confidence interval.
6. Figure 3, which sample was used for the characterization? Information should be provided.
Response: Thank you very much for the nice suggestions. Information has been added ( Page 9, Line 183-184).
7. Although Ag did not seem to contribute much to the antibacterial activity, it would still be beneficial to discuss the reasons. The authors claimed that it was possibly due to Ag agglomeration, however, no data was provided to support the hypothesis. Would the size of ZnO (Figure 2 shows samples have different sizes) have any effect? More discussions are needed. Referring to previous studies would also be helpful.
Response: Thank you very much for the nice suggestions. Thank you very much for the nice suggestions. A new discussion of the data has been introduced, providing a specific biography in the discussion. (Page 15, 293-296) and (Page 16, 315-323).
Author Response File: Author Response.docx
Round 2
Reviewer 1 Report
Thanks for the revision.
Reviewer 2 Report
The authors performed the modifications proposed by the Reviewer and improved the manuscript.
