Effective Detoxification of Aflatoxin B1 and Ochratoxin A Using Magnetic Graphene Oxide Nanocomposite: Isotherm and Kinetic Study
Round 1
Reviewer 1 Report
The work applies response surface methodology (RSM) to optimize the influence of pH within the range of 3 to 7, time (3‐7 h) and temperature (30 ºC‐50 ºC), on the simultaneous detoxification of aflatoxin B1 (AFB1) and ochratoxin A (OTA) by using MGO. It is very interesting and meaningful. Therefore, I think it can be accepted after a minor revision. Here are some comments:
- The scale bar should be added in Figure 2.
- Figure 3 cannot be read clearly.
- Some graphene oxide related work should be cited, such as Electrochim. Acta 2018, 283, 1660; Electrochim. Acta 2018, 291, 242; Energy Stor. Mater. 2019, 23, 88; J. Alloy. Compd. 2017, 708, 1178.
Author Response
Response to Reviewer 1 Comments:
1: The scale bar should be added in Figure 2
Thank you for pointing this out. Correction has been revised and highlighted with the turquoise color accordingly.
2: Figure 3 cannot be read clearly.
Agree. The improved version of Figure 3 has been added.
3: Some graphene oxide related work should be cited, such as Electrochim. Acta 2018, 283, 1660; Electrochim. Acta 2018, 291, 242; Energy Stor. Mater. 2019, 23, 88; J. Alloy. Compd. 2017, 708, 1178.
As recommended, those articles that are closely relevant to our work have been cited (17 and 38) and highlighted with the turquoise color.
Author Response File: 
Author Response.pdf
Reviewer 2 Report
The paper present a thorough and significant isoterm and knietic study about detoxification of Aflatoxin B1 and Ochratoxin A using magnetic graphene oxide nanocomposites.
The study is well written and sufficiently detailed as it describes the MGO nanocomposite absorption of AFB1 and OTA simultaneously in animal feed. It is also accompanied by a numerical examination using RSM which revealed that there is an optimum point for detoxification of mycotoxins with MGO. It was also well revealed by analysis of adsorption mechanisms that the hydroxyl groups of MGO is predominantly responsible for binding mycotoxins.
The paper is considered to be acceptable for publishing in the journal Coatings.
Author Response
Dear Reviewer
We really appreciate you taking the time to review our article and your kind words.
Author Response File: Author Response.pdf
Reviewer 3 Report
Effective Detoxification of Aflatoxin B1 and Ochratoxin A using Magnetic Graphene Oxide Nanocomposite: Isotherm and Kinetic Study by Abbasi Pirouz et al., (coatings-1345048)
- The authors will have to make it clear in their response and the revised paper what the novelty of this work is as compared to the state of the art in the literature of other adsorption systems. This must include text related to either: 1) a novel material that has distinct advantages with respect to selectivity or capacity, 2) a novel theoretical treatment, and/or 3) an application that has not been addressed to date.
- It is not sufficient to describe another adsorbent for another "standard application". Whatever the advantage of the adsorbent material is (capacity, selectivity, etc.) must be backed up with comparison data with the state of the art in the literature. The current focus on characterization studies does not seem novel, there are many papers like this in the literature, where is the novelty. Adsorption kinetics is not new.
- What is the BET surface area, micropore volume, pore size distribution, of the material?
- What is the zeta potential of the materials and can you relate the adsorption capacities obtained to this value?
- Regeneration is an essential step in any type of adsorbent material. It would be necessary to perform these experiments to validate the results obtained and to determine the stability of the material.
- I recommend a full revision of the language in order to avoid further editorial work.
This paper needs a major revision.
Author Response
Response to Reviewer 3 Comments:
1: The authors will have to make it clear in their response and the revised paper what the novelty of this work is as compared to the state of the art in the literature of other adsorption systems. This must include text related to either: 1) a novel material that has distinct advantages with respect to selectivity or capacity, 2) a novel theoretical treatment, and/or 3) an application that has not been addressed to date.
We thank the reviewer for pointing this out. In this present study, in order to enhance capacity adsorption, we optimized different parameters such as pH, time, and temperature which play significant factors toward removal of mycotoxin by using Response Surface Methodology (RSM). According to the results, the adsorption capacities were significantly affected by pH. Therefore, the application of MGO for the detoxification of mycotoxins in animal feed has been investigated. To the best of our knowledge, this is the first report of the removal of mycotoxins in animal feed with MGO simultaneously. The correction has been revised and highlighted with green color.
2: It is not sufficient to describe another adsorbent for another "standard application". Whatever the advantage of the adsorbent material is (capacity, selectivity, etc.) must be backed up with comparison data with the state of the art in the literature.
Thank you for pointing this out. Perspective information has been added in introduction and highlighted with green color.
3: What is the BET surface area, micropore volume, pore size distribution, of the material?
Thank you for this suggestion. It would have been interesting to explore this aspect. However, in the case of our study, we stayed focus on figured out the optimum points of independent variables which have an effect on the detoxification of mycotoxins, in addition, investigated the mechanism of action with isotherm and kinetic study between MGO and mycotoxins. Therefore, the surface morphology, size, and dimensions of the prepared MGO were evaluated using microscopic techniques, namely FESEM and TEM.
4: What is the zeta potential of the materials and can you relate the adsorption capacities obtained to this value?
Thank you for highlighting this as an important point. In fact, after we released regarding the adsorbent and mycotoxins with stereochemistry and hydrophobic interaction. In the next step of our study, we have been evaluating the influence of the zeta potential of MGO and modified magnetic graphene oxide on the adsorption of mycotoxins.
5: Regeneration is an essential step in any type of adsorbent material. It would be necessary to perform these experiments to validate the results obtained and to determine the stability of the material.
Regeneration of MGO has not been carried out due to the following reason:
According to LD50 and the results of embryonic exposure in Zebrafish to mycotoxins after reduction with MGO did not produce any toxic effects in embryos zebrafish. Thus, it appears that adsorbent after reduction did not pose a significant developmental toxicity risk (Figure 1-2) and (Table 1). Nevertheless, in the current study, we did not report this result due to the paper with this data has been prepared and set to submit. (Figures and Table have been attached in pdf file).
6: I recommend a full revision of the language in order to avoid further editorial work.
As recommended, all spelling and grammatical errors have been corrected and highlighted with green color.
Author Response File: Author Response.pdf
Round 2
Reviewer 3 Report
The authors have made all the changes suggested by the reviewer. The manuscript is now of sufficient quality for publication.
