Examination of Non-Modified Carbon Fibre Bundle as an Electrode for Electrochemical Sensing

Round 1

Reviewer 1 Report

This paper reported non-modified carbon fiber bundle as an electrode for electrochemical sensing dopamine. Although being interesting, I find that there are some major scientific issues with the paper that require addressing prior to this being considered for publication in this journal. I have identified the main points for consideration below:

1.     This manuscript has some spelling typos, style errors and grammatical errors. Please carefully check the whole manuscript.

2.     In the introduction section, some recent references related to the advantages of electrochemical sensors are recommended to be cited, including Microchemical Journal 190 (2023) 108726; Microchemical Journal 179 (2022) 107515; Materials Today Chemistry 26 (2022) 101043.

3.     The sensing performance including linear response range and LOD should be compared with the previous reported electrodes.

4.     Dopamine (DA) and ascorbic acid (AA) often coexist with UA in biological samples, so the antiinterfering ability of DA and AA should be carefully investigated.

5.     The stability of the proposed sensor should be added in the revised manuscript.

6.     For a healthy human being, the normal concentration of dopamine is in the range of 0.01 – 1 μM. But the LOD is much higher than the dopamine level, so the applicability is very poor.

7.     I recommend the authors detect dopamine concentration in some real samples such as serum urine samples using the proposed sensor. In addition, the detection results for real samples should be validated by the classic analytical techniques.

Moderate editing of English language required

Author Response

Dear Reviewer,

Thank you for your insightful comments and suggestions. We appreciate the time and effort you have put into reviewing our manuscript. Please find our responses to your comments below:

1. We apologize for the spelling typos, style errors, and grammatical errors in the manuscript. We have thoroughly reviewed the manuscript and corrected these errors. We appreciate your patience and understanding in this matter.
2. We thank you for suggesting the recent references related to the advantages of electrochemical sensors. We have now included these references in the introduction section of our revised manuscript.
3. We agree with your suggestion to compare the sensing performance of our electrode with previous reports. We have now included a detailed comparison in the revised manuscript.
4. Your point about the coexistence of Dopamine (DA) and Ascorbic Acid (AA) with Uric Acid (UA) in biological samples is well taken. We have now included a discussion on the anti-interfering ability of DA and AA in the revised manuscript.
5. We appreciate your suggestion to include information on the stability of the proposed sensor. We have now added this information in the revised manuscript.
6. We understand your concern about the Limit of Detection (LOD) being higher than the normal dopamine level in a healthy human being. We have now discussed this limitation in the manuscript and suggested potential ways to improve the LOD in future work.
7. We appreciate your suggestion to validate the sensor's performance using real samples. However, due to resource constraints and the current scope of our study, we are unable to perform these additional experiments at this time. We agree that this would be a valuable direction for future research and have mentioned this in the discussion section of our revised manuscript.

We hope that our responses adequately address your comments and concerns. We are grateful for your constructive feedback, which has helped improve the quality of our manuscript.

 

Best regards,

Ausra Baradoke

Reviewer 2 Report

This manuscript describes a simple and cost-effective non-modified commercial carbon fiber microcylinder bundle method for producing carbon fibre bundle electrodes (CFMBs) that are highly stable and reproducible for electrochemical sensing applications. The CFMBs were integrated into a 3D-printed electrochemical cell and tested for dopamine detection. The experiments, characterization, and evaluation of electrochemical sensing for the manuscript were conducted well, but more characterization may need to confirm the crystallinity and surface nature of the CFMBs. The detailed comments are shown below,

1.     It is needed to conduct Raman spectroscopy or XRD for the CFMBs to confirm the crystalline nature of the material.

2.     The surface nature of the CFMS used in the 3D-printed electrochemical cell after and before the reaction also needs to examine. FTIR or XPS is enough to identify those surface groups. Which can easily correlate with the reaction and information of surface-confined redox species.

 

This manuscript can be accepted after a minor revision.

Author Response

Dear Reviewer,

Thank you for your constructive feedback and the time you have invested in reviewing our manuscript. We appreciate your positive comments on our work and your suggestions for further improvements. Please find our responses to your comments below:

1. We agree that Raman spectroscopy or XRD would provide valuable information about the crystalline nature of the CFMBs. However, due to the current constraints, we are unable to conduct these additional experiments at this time. We have, however, discussed the potential insights that such analyses could provide in the revised manuscript and plan to include these characterizations in our future work.
2. Your suggestion to examine the surface nature of the CFMBs used in the 3D-printed electrochemical cell both before and after the reaction is well taken. We understand that techniques such as FTIR or XPS could provide valuable information about surface groups and surface-confined redox species. However, similar to the first point, we are currently unable to perform these additional experiments. We have included a discussion on the potential benefits of such analyses in the revised manuscript and will consider these characterizations in our future research.

We are grateful for your positive evaluation of our manuscript and your suggestion for minor revisions. We believe that the manuscript has been improved based on your feedback, and we hope that it is now suitable for publication.

 

Best regards,

Ausra Baradoke

Reviewer 3 Report

Dear authors,

 

Manuscript coatings-2524872 entitled “Examination of Non-Modified Carbon Fibre Bundle as an Electrode for Electrochemical Sensing “ shows an interesting study for the development of a dopamine sensor. However, it recommends some modifications:

1) The choice of dopamine as an analyte is little addressed in the introduction. Therefore I suggest expanding this part to include a general discussion of the importance in research of also detecting dopamine precursors such as phenylalanine, tyrosine, (10.1109/TIM.2023.3284027, 10.1002/slct.202300269, 10.1002/elan.202200501, 10.1007/s00604-023-05648-8, 10.1016/j.mtcomm.2023.106036, 10.1016/j.bios.2023.115360).

2) Figure 2 if the image quality can be increased.

3) Re-check the text for small typing errors.

4) Figure 4 should be improved.

5) In the EIS analysis, I do not see the comparison between your sensor and the bare electrode (SPE). This figure allows you to see the difference after modification.

6) Since the error bar cannot be appreciated from the figures you could write the value in the caption for completeness.

7) In stability and reproducibility, you could include the RSD calculation.

8) Insert the comparison between the bare sensor and the modified sensor in the dopamine detection at a given concentration so as to state that after the modification the sensor works better.

9) Lines 357 to 370 make a comparison between the LODs. In my opinion it is better to draw up a table.

10) I would also include a table comparing several recent sensors in the literature and yours in dopamine detection to confirm that this study shows good results.

11) Section 3.6 you talk about selectivity but do not report data. What did you test? What answers did you get?

12) Stability and reproducibility data should also be conducted in dopamine sensing.

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Author Response

Dear Reviewer,

We sincerely appreciate your careful review and constructive feedback on our manuscript. Your comments have provided us with valuable insights that will undoubtedly enhance the quality of our work. Please find our responses to your comments below:

1. We agree that a more detailed discussion on the importance of detecting dopamine and its precursors would add value to our introduction. We have expanded this section in the revised manuscript, incorporating the suggested references.
2. We apologize for the low quality of Figure 2. We have now replaced it with a higher resolution image in the revised manuscript.
3. We appreciate your attention to detail. We have thoroughly reviewed the manuscript and corrected all typing errors.
4. We have taken your suggestion into account and improved Figure 4 for better clarity and understanding.
5. Your suggestion to include a comparison between our sensor and the bare electrode (SPE) in the EIS analysis is well taken. We have now included this comparison in the revised manuscript.
6. We apologize for the oversight regarding the error bars. We have now included the error values in the figure captions for completeness.
7. We agree that including the Relative Standard Deviation (RSD) calculation in the stability and reproducibility section would be beneficial. We have now included this in the revised manuscript.
8. We have included a comparison between the bare sensor and the modified sensor for dopamine detection at a given concentration in the revised manuscript, as per your suggestion.
9. We agree that a table would make the comparison of LODs clearer. We have now included a table for this purpose in the revised manuscript.
10. We appreciate your suggestion to include a table comparing our sensor with several recent sensors in the literature for dopamine detection. We have now included this table in the revised manuscript.
11. We apologize for the oversight in the selectivity section. We have now included the data and discussed the tests we conducted and the results we obtained.
12. We agree that stability and reproducibility data should also be conducted in dopamine sensing. However, due to current constraints, we are unable to perform these additional experiments at this time. We have discussed this limitation in the revised manuscript and suggested it as a direction for future research.

We hope that our responses adequately address your comments and concerns. We are grateful for your constructive feedback, which has helped improve the quality of our manuscript.

 

Best regards,

Ausra Baradoke

Round 2

Reviewer 1 Report

The authors have addressed all my comments, so I recommend it for publication in this journal.

Moderate editing of English language required.

Reviewer 3 Report

The authors have satisfactorily answered the questions posed. I recommend their publication.