A Novel High-Sensitivity Terahertz Microstructure Fiber Biosensor for Detecting Cancer Cells
Round 1
Reviewer 1 Report
The paper presents a promising microstructure fiber for bio-sensing application is proposed. The literature review is through including various reported research works.
It is not clear how the results in Fig. 7 have been obtained. Were those experimental or simulation results? If those are from experimental results, please specify the procedure of getting the parameters and coming up with the results. And the accuracy of the cancer detection method is not mentioned based on the refractive index or the relative sensitivity. Can there be a large variety of tissue refractive indexes among different groups of patients? In other words, refractive index measurement is a reliable way of detecting cancer cells?
Was the microstructure fiber sensor design also considered for its fabrication? The paper discussed various performance figures of the proposed sensor design. However, is it feasible to generate the proposed structure?
Miscellaneous items
- It will be good to briefly explain some terms (e.g., EML, CL, % sensitivity, etc.) for casual readers before those are discussed in section 2.2.
- Lines 74-75: What is the problemed mentioned in the sentence?
- Lines 142-143: c and l are separately explained even though it is written lc in the equation (1).
Author Response
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Author Response File: 
Author Response.pdf
Reviewer 2 Report
The manuscript by Yao et al. demonstrated a newly designed microstructure fiber for THz spectroscopy (sensing). The manuscript is well written with excellent structures, detailed instructions of design, experiments, and results analysis. It is a systematic study including comprehensive discussion on the parameters of fiber for sensitivity and loss optimization. I believe these results would be highly interesting for researchers in the field and suggest publication at current stage. I do not have many comments on the study. I think there are some minor problems about language. Some grammatic problems like: “especially, the relative sensitivity is up to 99.8 % can be …” and “the search for an efficient way to .. is currently being pursued” (duplication). It would be nice if these can be corrected in the final version.
Author Response
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Reviewer 3 Report
The manuscript presents a microstructure fiber biosensor with porous-core structures for detection of cancer cells. For this sensor, the numerical aperture, the power fraction, the relative sensitivity, the effective material and the confinement losses, and effective area are investigated and simulated. This area has been intensely investigated in the last few years, and now a key novelty or thorough investigations are needed. Although the reported results are probably correct, the reviewer feels that the overall analysis is not enough and the quality of the manuscript as it stands, is not sufficient for publication in Photonics. The comments are as follows:
1. Investigated parameters of the biosensor including the numerical aperture, the power fraction, the relative sensitivity, the effective material loss, the confinement loss, and effective area should be completed. The detection limit and quality factor are two important parameters which are not investigated.
2. In lines 84-85: "Here, report a simple and efficient design of multi-core MSF sensor for the biosensing, which is feasible to fabricate through 3D printing preparation process." It is strongly recommended to add some experimental results to highlight the novelty.
3. In section 3.1: "Optimization of structural parameters in MSF". There is no optimization algorithm and it seems a try and error method. The results are presented for the changes of the fiber core diameter, d2, and d3, and it is mentioned that "After determining the optimal core diameter, we fixed Dcore = 800 μm, d1 = 25 μm, d3 = 235 100 μm, and numerically simulated the column width (d2) of the cladding." (lines 235-236). This report is not an efficient method to optimize the parameters.
4. The environmental effects on the biosensor performance should be considered and addressed.
5. The manuscript should be carefully edited. The references need to be complete by adding the page range.
6. Table 1 should be completed by adding detection limit and quality factor (simulations and experiments).
Author Response
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Author Response File: Author Response.pdf
Round 2
Reviewer 3 Report
The authors have tried to address the comments, and therefore, the revised manuscript can be accepted.
