This paper reported a novel electrochemical sensor for mercury (II) detection using MoS2@MWCNT composite. Although being interesting, I find that there are some major 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. The manuscript has some spelling, subscript, and grammar errors. Please carefully check the whole manuscript.
2. Some recent references related to MWCNT-based electrochemical sensors or heavy ion metal electrochemical sensor are recommended to be cited, such as 10.1016/j.foodchem.2023.137753; 10.1016/j.microc.2024.110673; ACS Appl. Nano Mater. 2023, 6, 17040-17052; ACS Appl. Nano Mater. 2023, 6, 19403-19413; Microchemical Journal 179 (2022) 107515.
3. Raman spectrum of MoS2@MWCNT should be added in the Fig 1. In addition, EDX mapping image of MoS2@MWCNT should also be added.
4. XRD patterns of MoS2, MWCNT and MoS2@MWCNT should be provided in the revised manuscript.
5.different heavy metal ions, such as Pb2+, Co2+, As3+, and F-……, F- is not heavy metal ion. Please check this sentence.
6. ppb is not SI Unit, please replace it with μM.
7. Please check typos such as Hg+2.
8. The electroactive surface area and charge transfer resistance for different electrodes should be provided in the revised manuscript.
9. The reproducibility of the MoS2@MWCNT/GCE should be added in the revised manuscript.
10. How about deposition potential, deposition time and buffer pH on the response peak of Hg(II)?
11. The real sample detection is missing in the present manuscript. Please add it in the revised manuscript. In addition, the detection results should be verified by the classic technique such as ICP-MS and AAS.
12. The sensing performance of the MoS2@MWCNT/GCE should be compared with the previously reported ones.
13. In Fig. 3, Why were the response peak current of Hg2+ not linear with its concentration?
14. Why did the proposed MoS2@MWCNT/GCE demonstrate the selectivity and stability?