Influence of Carbon Quantum Dots on the Biome

Round 1

Reviewer 1 Report

This paper highlights some critical points and open questions about the impact of the CQDs on plants and living organisms. As stated by the authors the "knowledge about their environmental impacts is practically in its infancy" and despite some few recent publications cited in this opinion letter - i.e. the positive effect of these nanoparticles on rice and lettuce plants growth- the use of CQDs are still far to be really employed in a sustainable way on industrial / agricultural scale.

In general, however, I would not have been so categorical in highlight only the negative doubts related to the use of nanoparticles on the field even though I fully agree with the authors on invoking caution for a real application.

Despite my "more positive view" and "personal opinion", the paper is timing, interesting and well written and thus worth of publishing. I only suggest to the authors to  include/explicit/discuss (even using a figure-like representation) on the conclusion a list of issues/topics/challenges that will need to be clarify in in order to help readers/researchers to focus on future studies.

Author Response

This paper highlights some critical points and open questions about the impact of the CQDs on plants and living organisms. As stated by the authors the "knowledge about their environmental impacts is practically in its infancy" and despite some few recent publications cited in this opinion letter - i.e. the positive effect of these nanoparticles on rice and lettuce plants growth- the use of CQDs are still far to be really employed in a sustainable way on industrial / agricultural scale.

In general, however, I would not have been so categorical in highlight only the negative doubts related to the use of nanoparticles on the field even though I fully agree with the authors on invoking caution for a real application.

We thank the reviewer for this observation. There are too many articles that espouse the positive aspects of carbon quantum dots (which we have, in fact, cited in our MS.) and as a result, researchers in the field have been acclimatized to using them "as-is". I.e., without examining in details the toxicity, structure, fate, transport in the biome. It is our desire to highlight the potential risk to the biome when such parameters are not sufficiently established. We apologize if its appears overtly negative.

Despite my "more positive view" and "personal opinion", the paper is timing, interesting and well written and thus worth of publishing. I only suggest to the authors to include/explicit/discuss (even using a figure-like representation) on the conclusion a list of issues/topics/challenges that will need to be clarify in in order to help readers/researchers to focus on future studies.

 We thank the reviewer for this vital suggestion. We have included a few points on this in the conclusion section. Scheme 1 (which is again referred to in the edited conclusion, provides a "guide" for the safer use of CQD's rather than their current "as-is" use.

Reviewer 2 Report

The authors have briefly reviewed and discussed the potential implications of CQDs on the environment. Overall, this is a very interesting piece of exceptional timely importance. Although short, it builds on adequate literature support and the concerns raised by the authors are well substantiated. I only have two minor remarks (see below).

Language - although the manuscript is generally well-written, it requires a revision for some sentences could be polished. For instance, the last paragraph of the Introduction repeats "environmentally" three times; and Conclusions (line 112-115), the sentence "Zheng et al reported that (...) leaf number and foliar area.", needs an overhaul.

References - According to the journal's guidelines, in-text references must be numbered in order of appearance and placed in square brackets. Furthermore, the dot at the end of the sentence must come after the citation, not before.

Author Response

The authors have briefly reviewed and discussed the potential implications of CQDs on the environment. Overall, this is a very interesting piece of exceptional timely importance. Although short, it builds on adequate literature support and the concerns raised by the authors are well substantiated. I only have two minor remarks (see below).

Language - although the manuscript is generally well-written, it requires a revision for some sentences could be polished. For instance, the last paragraph of the Introduction repeats "environmentally" three times; and Conclusions (line 112-115), the sentence "Zheng et al reported that (...) leaf number and foliar area.", needs an overhaul.

Dear Referee: Thank you. You are correct. we have now modified the sentence.

We have also heavily overhauled the sentence involving the Zheng citation. It makes more sense now.

References - According to the journal's guidelines, in-text references must be numbered in order of appearance and placed in square brackets.

Thank you. we will do so if the MS is accepted. We had, I believe, asked for prior permission on this.