Inactivation and Degradation of Influenza A Virus on the Surface of Photoactive Self-Cleaning Cotton Fabric Functionalized with Nanocrystalline TiO2
, Grigory Stepanov 3, Mariia Sergeeva 4, Maria Solovyeva 1,2, Evgenii Zhuravlev 1,3, Andrey Komissarov 4, Vladimir Richter 3 and Denis Kozlov 1,2
Round 1
Reviewer 1 Report
The research offers the study of TiO2 nanoparticles synthesized on cotton in the elimination of the Infleunza A virus.
In general, it is good research, with a novel idea when working with the influenza A virus that has not been adequately addressed by the scientific community in recent years. The presentation of the data is of excellent quality, and in general the publication has merit to be published. However, I believe that there are some issues that need to be improved before publication is approved.
- The introduction I think should be improved. There is a lack of information (the little that has been published) regarding the use of TiO2, TiO2 on fabric, TiO2 synthesized on other types of supports other than fabric or other types of nanomaterials that have been used in the inactivation/elimination of the virus of the influenza A. In a quick review it is possible to find some evidence on this, and I believe that it should serve as support for the approach of the investigation, as a point of comparison of the efficiencies of this investigation with the others, and that it further supports the conclusions.
- Although the characterization of TiO2 is adequate, I believe that the available information could be further exploited. For example, it is possible to make a particle size histogram with the information obtained from the SEM (or TEM) images or to generate a Tauc plot from the diffuse reflectance data to obtain the band-gap of the synthesized TiO2.
- In graph 3, especially in Figure 3.b, it seems to me that some comment is needed regarding the statistical differences (if any) between cotton fabric under UV-A and Photoreactive fabric under UV-A. At first glance it seems that there are no important differences in the first 20 minutes. If it is true that there are no important differences, how could this be explained?
- In line 335 it is mentioned that "TiO2-mediated photocatalytic oxidation has no selectivity", but there are no references regarding this, nor are there any experiments with scavengers to support this. Consider that it is generally considered that, for example, the ·OH does not have selectivity, but the other species that can be produced in photocatalysis (1O2, O2·-, electrons, holes, etc.)
- In lines 366 and 337 it is mentioned that there are other cases that present a behavior contrary to that observed in their investigation in relation to the increase of the Cq values ​​with respect to the time of UV irradiation. Evidence of these "other cases" could be added.
- How does the fact that the virus inactivation test was done in the presence of proteins, while the virus degradation test was done in the culture medium, affect the comparison of results?
- Figure 5 seems to me that it does not have the necessary evidence to state what is indicated. For this it seems to me that the ideal would be to have some EPR analysis, or with some simple analysis by UV-visible spectrophotometry that detects these reactive species, or by a study using scavenger molecules. If it is not possible to carry out these experiments, at least mention other works in which these studies have been carried out as a basis for supporting this Figure.
- In the paragraph between lines 428 and 442 it is mentioned that the synthesis of TiO2-N was made, and its efficiency in the relative reduction of the virus is inserted in Figure S3 using visible radiation. Although it is not the main focus of the publication, I think this material (TiO2-N) should have some figure of its characterization, but more importantly, a graph with information on its diffraction reflectance spectrum and a Tauc graph. This will contribute to what is mentioned in this paragraph.
Some other minor fixes that need to be done are:
- Scientific names of microorganisms must be presented in italics (in the text and in supplementary material)
- Avoid the use of "less formal" language as in line 66 (researcher's interest)
- Reference 46 on line 135 I consider should not be included. Reference 47 is sufficient.
- To the sentence of line 305 and 306 related to UV regions, references should be added
- Check in the references that the chemical formulas are with their respective subscripts or superscripts
Author Response
Responses to Reviewer #1
Comment: In general, it is good research, with a novel idea when working with the influenza A virus that has not been adequately addressed by the scientific community in recent years. The presentation of the data is of excellent quality, and in general the publication has merit to be published
Response: Thank you for your appreciation of our work and your valuable comments that helped us improve this paper. A detailed response to each comment is provided below.
Comment: The introduction I think should be improved. There is a lack of information (the little that has been published) regarding the use of TiO2, TiO2 on fabric, TiO2 synthesized on other types of supports other than fabric or other types of nanomaterials that have been used in the inactivation/elimination of the virus of the influenza A. In a quick review it is possible to find some evidence on this, and I believe that it should serve as support for the approach of the investigation, as a point of comparison of the efficiencies of this investigation with the others, and that it further supports the conclusions.
Response: We have added to Introduction specific information on inactivation of influenza A virus over photocatalytic materials. Please find the revised version of manuscript.
Comment: Although the characterization of TiO2 is adequate, I believe that the available information could be further exploited. For example, it is possible to make a particle size histogram with the information obtained from the SEM (or TEM) images or to generate a Tauc plot from the diffuse reflectance data to obtain the band-gap of the synthesized TiO2.
Response: It is difficult to plot a histogram of particle size distribution using SEM images due to low contrast between components (cotton and TiO2) because they are both non-conductive materials. At the same time, in the case of TEM analysis, local degradation of material and aggregation of particles occur in the focus point of electron beam due to a low stability of cotton support.
We have added a description of structure and size of attached particles to the text of manuscript. According to your suggestion, we have added Tauc plots to Fig.3c and discussed the values of optical band gaps in the text. Please find the revised version of manuscript.
Comment: In graph 3, especially in Figure 3.b, it seems to me that some comment is needed regarding the statistical differences (if any) between cotton fabric under UV-A and Photoreactive fabric under UV-A. At first glance it seems that there are no important differences in the first 20 minutes. If it is true that there are no important differences, how could this be explained?
Response: All experimental data in Fig.3 are presented with error bars estimated in three (at least) repeats. It allows us to identify statistically significant differences.
Small differences between cotton and photoactive fabrics under irradiation for first 10-20 min is related to a low rate of virus degradation in the case of a high concentration of protein, because protein molecules compete with virions for adsorption sites. Further irradiation increases the degradation ratio, and a statistically significant difference between the materials is observed. In the revised version, we have more discussed this aspect. Please find the revised version.
Comment: In line 335 it is mentioned that "TiO2-mediated photocatalytic oxidation has no selectivity", but there are no references regarding this, nor are there any experiments with scavengers to support this. Consider that it is generally considered that, for example, the ·OH does not have selectivity, but the other species that can be produced in photocatalysis (1O2, O2·-, electrons, holes, etc.).
Response: Yes, we completely agree, but in the case of TiO2, OH-radicals are regarded as the main species that provide oxidation reactions. We have added the reference to support this statement. Please find the revised version of manuscript.
Comment: In lines 366 and 337 it is mentioned that there are other cases that present a behavior contrary to that observed in their investigation in relation to the increase of the Cq values ​​with respect to the time of UV irradiation. Evidence of these "other cases" could be added.
Response: In this sentence, «other cases» mean Cq data for other samples (cotton fabric, cotton fabric under UV and photoactive fabric) showed in Fig. 4a. We have corrected the text. Please find the revised version of manuscript.
Comment: How does the fact that the virus inactivation test was done in the presence of proteins, while the virus degradation test was done in the culture medium, affect the comparison of results?
Response: Although the experiments, discussed in section 2.2. and 2.4, were conducted under different conditions, they show different aspects of process and complement each other to draw overall picture for transformation of influenza virus due to photocatalytic effect.
Comment: Figure 5 seems to me that it does not have the necessary evidence to state what is indicated. For this it seems to me that the ideal would be to have some EPR analysis, or with some simple analysis by UV-visible spectrophotometry that detects these reactive species, or by a study using scavenger molecules. If it is not possible to carry out these experiments, at least mention other works in which these studies have been carried out as a basis for supporting this Figure.
Response: We have added references to studies that prove the proposed scheme of virus degradation.
Comment: In the paragraph between lines 428 and 442 it is mentioned that the synthesis of TiO2-N was made, and its efficiency in the relative reduction of the virus is inserted in Figure S3 using visible radiation. Although it is not the main focus of the publication, I think this material (TiO2-N) should have some figure of its characterization, but more importantly, a graph with information on its diffraction reflectance spectrum and a Tauc graph. This will contribute to what is mentioned in this paragraph.
Response: Yes, discussion of materials prepared using TiO2-N is beyond the scope of this article, and the mentioned paragraph only underlines prospects for further improvement of concerning materials. Detailed characterization of TiO2-N was made in our previous paper referenced in this paragraph. To improve reading, we have added information on the absorption edge of TiO2-N to the text in this paragraph. Please find the revised version of manuscript.
Comment: Some other minor fixes that need to be done are:
- Scientific names of microorganisms must be presented in italics (in the text and in supplementary material)
- Avoid the use of "less formal" language as in line 66 (researcher's interest)
- Reference 46 on line 135 I consider should not be included. Reference 47 is sufficient.
- To the sentence of line 305 and 306 related to UV regions, references should be added
- Check in the references that the chemical formulas are with their respective subscripts or superscripts.
Response: We have corrected all mentioned points.
Reviewer 2 Report
The research results described in the work entitled "Inactivation and Degradation of Influenza A Virus on the Surface of Photoactive Self-Cleaning Cotton Fabric Functionalized with Nanocrystalline TiO2 are not new to science. However, in my opinion, the results described are interesting, valuable and worth publishing.
But the manuscript has many drawbacks and should be corrected. The manuscript is written like a report, not a scientific article.
Discussion should be edited from scratch. The worst chapter is the conclusions. Conclusions should describe the results of the research, not a summary of the numerical results.
In my opinion describing the results obteined in the presence TiO2-N is redundant. It is not appropriate to describe these experiments in a supplement. Moreover, the manuscript should be carefully checked before sending to the journal. It contains many minor errors in the text and in the captions of the figures.
Author Response
Responses to Reviewer #2
Comment: The research results described in the work entitled "Inactivation and Degradation of Influenza A Virus on the Surface of Photoactive Self-Cleaning Cotton Fabric Functionalized with Nanocrystalline TiO2 are not new to science. However, in my opinion, the results described are interesting, valuable and worth publishing.
Response: Thank you for appreciating our work.
Comment: But the manuscript has many drawbacks and should be corrected. The manuscript is written like a report, not a scientific article. Discussion should be edited from scratch.
Response: We disagree that the submitted manuscript looks like a report because it contains discussion of all aspects of considering topic, including the preparation of material, relationships between its characteristics and functional properties, its effect on transformation of target contaminant in several systems based on the data of different experimental techniques. All sections are connected by logic and aim to illustrate the mechanism of virus degradation due to the photocatalytic effect on the surface of cotton fabric functionalized with TiO2. In the revised version of manuscript, we have more discussed the results to improve the quality of presentation. Please find the revised version.
Comment: The worst chapter is the conclusions. Conclusions should describe the results of the research, not a summary of the numerical results.
Response: The conclusions have been corrected. Please find the revised version of manuscript.
Comment: In my opinion describing the results obteined in the presence TiO2-N is redundant. It is not appropriate to describe these experiments in a supplement.
Response: Yes, discussion of the materials prepared using TiO2-N is beyond the scope of this article, but we believe this information is important for showing the prospects for further improvement of concerning self-cleaning materials and their practical application. In the revised version, we have added information on the absorption edge of TiO2-N to better express this aspect.
Comment: Moreover, the manuscript should be carefully checked before sending to the journal. It contains many minor errors in the text and in the captions of the figures.
Response: We have read the text and corrected some errors. Final correction will be made during proofreading step.
Reviewer 3 Report
The article presents the photocatalytic effect of titania nanoparticles deposited on fabrics regarding viruses and other substances. This work is well presented and I consider that the investigation is thorough, convincing and complete. I recommend publication of this work as is.
Author Response
Responses to Reviewer #3
Comment: The article presents the photocatalytic effect of titania nanoparticles deposited on fabrics regarding viruses and other substances. This work is well presented and I consider that the investigation is thorough, convincing and complete. I recommend publication of this work as is.
Response: Thank you for your appreciation of our work.
Reviewer 4 Report
This is a very interesting and important article that can be recommended for publication, but after clarifying and detailing some parts of the text.
1. Introduction. More information about main object of the current investigation (TiO2) is required. In particular, how important is the structure and size of nanostructures? Furthermore, absolutely necessary to reflect what has been done in recent years. See, for example, few recent MDPI papers:
Serga, V.; Burve, R.; Krumina, A. et al . Extraction–Pyrolytic Method for TiO2 Polymorphs Production. Crystals 2021, 11, 431. https://doi.org/10.3390/cryst11040431
Soundarya, T.L.; Jayalakshmi, T.; Alsaiari, M.A.; et al Ionic Liquid-Aided Synthesis of Anatase TiO2 Nanoparticles: Photocatalytic Water Splitting and Electrochemical Applications. Crystals 2022, 12, 1133. https://doi.org/10.3390/cryst12081133
and references therein.
2. Material and methods are described in detail and contain all the necessary information
3. Fig.1. How stable are SEM pictures over time and are there any hints of aging?
4. Figure 2a. It would be useful to compare the diffraction data with literature data.
In general, the manuscript is very interesting and can be considered for publication after constructive reflection on the above comments.
Author Response
Responses to Reviewer #4
Comment: This is a very interesting and important article that can be recommended for publication, but after clarifying and detailing some parts of the text… In general, the manuscript is very interesting and can be considered for publication after constructive reflection on the above comments.
Response: Thank you for appreciating our work. We have revised the manuscript to address your comments.
Comment: 1. Introduction. More information about main object of the current investigation (TiO2) is required. In particular, how important is the structure and size of nanostructures? Furthermore, absolutely necessary to reflect what has been done in recent years. See, for example, few recent MDPI papers:
Serga, V.; Burve, R.; Krumina, A. et al . Extraction–Pyrolytic Method for TiO2 Polymorphs Production. Crystals 2021, 11, 431. https://doi.org/10.3390/cryst11040431
Soundarya, T.L.; Jayalakshmi, T.; Alsaiari, M.A.; et al Ionic Liquid-Aided Synthesis of Anatase TiO2 Nanoparticles: Photocatalytic Water Splitting and Electrochemical Applications. Crystals 2022, 12, 1133. https://doi.org/10.3390/cryst12081133
and references therein.
Response: The present study is focused on the inactivation and degradation of influenza A virus using the photocatalytic effect. Therefore, in Introduction we did not go into detail of TiO2 photocatalysts, but we focused on the degradation of biological objects over self-cleaning materials. According to your recommendation, we have added to Introduction the mentioned papers to illustrate the application of TiO2 in various types of processes and to underline the effect of its characteristics on the photocatalytic activity. Also, we have added specific information on inactivation of influenza A virus over TiO2-based materials. Please find the revised version of manuscript.
Comment: 2. Material and methods are described in detail and contain all the necessary information
Response: Thank you for appreciating our work.
Comment: 3. How stable are SEM pictures over time and are there any hints of aging?
Response: Because all the materials were used after washing in an automated washing machine, only strongly attached TiO2 particles remained on the surface of cotton fibers, and no aggregation of these particles was detected during SEM analysis even at a high accelerating voltage. Therefore, no substantial change in SEM images was observed over time (however, in the case of TEM technique it can occur but mainly due to a low stability of cotton support itself). The photocatalytic activity of materials in a test reaction of acetone oxidation had similar values in a series of measurements over the year that also supports the stability of prepared materials. We have added this information to text in the revised version of manuscript.
Comment: 4. It would be useful to compare the diffraction data with literature data.
Response: Thank you for indicating this aspect. We have added refences to the paper concerning diffraction data of cellulose and to the papers regarding anatase-based materials. Also, we have indicated JCPDS card number of anatase in Fig.2a.
Round 2
Reviewer 1 Report
Dear authors, according to the corrections you have made, I think that the publication has the characteristics to be published. Congratulations for your work.
Best regards.
Author Response
Thank you for your help in improving the article.
Reviewer 4 Report
The authors have strongly improved their manuscript which now can be recommended for publication
Author Response
Thank you for your help in improving the article.
