Microfluidic devices for the detection of viruses: aspects of emergency fabrication during the COVID-19 pandemic and other outbreaks

Extensive testing of populations against COVID-19 has been suggested as a game-changer quest to control the spread of this contagious disease and to avoid further disruption in our social, healthcare and economical systems. Nonetheless, testing millions of people for a new virus brings about quite a few challenges. The development of effective tests for the new coronavirus has become a worldwide task that relies on recent discoveries and lessons learned from past outbreaks. In this work, we review the most recent publications on microfluidics devices for the detection of viruses. The topics of discussion include different detection approaches, methods of signalling and fabrication techniques. Besides the miniaturization of traditional benchtop detection assays, approaches such as electrochemical analyses, field-effect transistors and resistive pulse sensors are considered. For emergency fabrication of quick test kits, the local capabilities must be evaluated, and the joint work of universities, industries, and governments seems to be an unequivocal necessity.

I have read your article. Of course the topic of the review is of interest to not only research community but also for general public. To make it widely acceptable and easy for readers to understand, the article should undergo several structural changes (see my comment below): 1.
The review is on: microfluidic devices for viruses detection. However, the authors have spent the whole of 1st paragraph (introduction section) only on coronavirus. Although it is interesting but there is no need to focus that much on this topic alone. Therefore I strongly suggest the authors to cut short this to not more than 4-5 lines.

2.
Again in the section of "Recent outbreaks", a lot of information is provided in paragraph 2 (page 6). All this information can be found in various relevant articles. I suggest the authors to cut short this to not more than 4-5 lines.
3. Figure 1: the authors say that "searches containing the word: microfluidic, devices, virus and detection. Of course the numbers will be high (it is expected as it covers different topics). I think as this review is on "microfluidics for virus detection". This figure should only represent the list of publications dealing with "Microfluidics for virus detection" as such. Then we will understand the trend how microfluidics are used for virus detection. Otherwise this is a misleading figure. The figure should be remodified. 4. P21, L34: analysis (see Figure 3Error! Reference source not found). Please check this. 5.
I find the organization of the article should be better. The review should be easy to follow in its structure. The authors need to restructure the article. For e.g. they should have discussed about the microfluidic fabrication etc. after the section of "Recent outbreaks". Then they should talk about detection of various viruses using microfluidic devices. In this they should have categorized papers more clearly with various subheading. Then finally come to conclusion. 6.
In terms of conclusion: I feel they should have discussed more scientific conclusions for various virus detection using microfluidics then how they perceive some of the potential possibilities for COVID19 detection from the existing literature etc. The purpose of this review is to show way for researchers to exploit the microfluidic devices for virus detection and especially in current scenario the COVID19 detection. This is missing in the current conclusion section 7. General comment: Grammar should be crosschecked Decision letter (RSPA-2020-0398.R0)

07-Aug-2020
Dear Dr Berkenbrock The Reviews Editor of Proceedings A has now received comments from referees on the above paper and would like you to revise it in accordance with their suggestions which can be found below (not including confidential reports to the Reviews Editor).
Please submit a copy of your revised paper within four weeks -if we do not hear from you within this time then it will be assumed that the paper has been withdrawn. In exceptional circumstances, extensions may be possible if agreed with the Editorial Office in advance.
Please note that it is the editorial policy of Proceedings A to offer authors one round of revision in which to address changes requested by referees. If the revisions are not considered satisfactory by the Reviews Editor, then the paper will be rejected, and not considered further for publication by the journal. In the event that the author chooses not to address a referee's comments, and no scientific justification is included in their cover letter for this omission, it is at the discretion of the Editor whether to continue considering the manuscript.
In addition to addressing all of the reviewers' and editor's comments please also ensure that your revised manuscript contains the following sections before the reference list:

• Acknowledgements • Funding statement
To revise your manuscript, log into http://mc.manuscriptcentral.com/prsa and enter your Author Centre, where you will find your manuscript title listed under "Manuscripts with Decisions." Under "Actions," click on "Create a Revision." Your manuscript number has been appended to denote a revision.
You will be unable to make your revisions on the originally submitted version of the manuscript. Instead, revise your manuscript and upload a new version through your Author Centre.
When submitting your revised manuscript, you will be able to respond to the comments made by the referee(s) and upload a file "Response to Referees" in "Section 6 -File Upload". Please use this to document how you have responded to the comments, and the adjustments you have made. In order to expedite the processing of the revised manuscript, please be as specific as possible in your response to the referee(s).
IMPORTANT: Your original files are available to you when you upload your revised manuscript. Please delete any unnecessary previous files before uploading your revised version.
When revising your paper please ensure that it remains under 28 pages long. Your paper has been ESTIMATED to be 22 pages.
Once again, thank you for submitting your manuscript to Proc. R. Soc. A and I look forward to receiving your revision. If you have any questions at all, please do not hesitate to get in touch. Comments to the Author(s) This paper reviews recent developments on microfluidic devices for viruses detection. The authors discuss different detection approaches, methods of signalling and fabrication techniques. This review paper is very informative and helpful for readers to chose and develop suitable miniaturized detectors for specific virus detection tasks. I would like to highly recommend this review article to be accepted by Proceedings A after minor revisions. 1) Page 2, lines 43-49, Introduction, I suggest that the authors update the infection cases and deaths of US and worldwide according to the latest information;

Yours sincerely
2) Page 3, line 34, "Many microfluidic devices are been…", here, I would suggest to replace the word "are" by "have"; 3) Page 19, line 34, "References sources not found", authors need to check the correct the citation here.
Referee: 2 Dear authors, I have read your article. Of course the topic of the review is of interest to not only to the research community but also to the general public. To make it widely acceptable and easy for readers to understand, the article should undergo several structural changes, see my comments below.
1. The review is on `Microfluidic devices for viruses detection'. However, the authors spend the whole 1st paragraph (Introduction section) on the coronavirus only. This is interesting but there is no need to focus that much on this topic alone. Therefore I strongly suggest that the authors shorten this part to not more than 4-5 lines.
2. In the section on "Recent outbreaks", a lot of information is provided in paragraph 2 (page 6). All this information can be found in various relevant articles. I suggest that the authors shorten this part to not more than 4-5 lines.
3. Figure 1: the authors mention "searches containing the word: microfluidic, devices, virus and detection". Of course the search numbers will be high: this is expected because the search covers different topics. This review is on "microfluidics for virus detection", and the search should be on this theme, within quotes. The figure should only represent the list of publications dealing with "Microfluidics for virus detection" as such. Then we will understand the trends on how microfluidics are used for virus detection. Otherwise a misleading figure is presented and it should be remodified.
4. P21, L34: analysis (see Figure 3Error! Reference source not found). Please check this. 5. I find the organization of the article could be improved. The review should be easy to follow in its structure and the authors need to restructure the article. For example, they should discuss the microfluidic fabrication etc. after the section on "Recent outbreaks". Then, they should talk about the detection of various viruses using microfluidic devices. In that part, they should sort papers more clearly with into categories with clear subheading. Then finally they can come to conclusion.
6. About the conclusion: I feel the authors should have presented and discussed more scientifically-minded conclusions for various virus detection modes using microfluidics; and then explain how they perceive some of the potential possibilities for COVID19 detection from the existing literature, etc. Indeed, the purpose of this review is to show ways for researchers to exploit microfluidic devices for virus detection and especially in the current scenario of COVID19 detection. This aspect is missing in the current conclusion section 7. General comment: The grammar should be checked throughout.

Is the paper of sufficient general interest? Excellent
Is the overall quality of the paper suitable? Good

Can the paper be shortened without overall detriment to the main message? Yes
Do you think some of the material would be more appropriate as an electronic appendix? No

Recommendation?
Accept as is

Comments to the Author(s)
Authors have addressed all my comments properly.

Is the paper of sufficient general interest? Excellent
Is the overall quality of the paper suitable? Good Can the paper be shortened without overall detriment to the main message? Yes Do you think some of the material would be more appropriate as an electronic appendix? No

Comments to the Author(s)
The authors have done the necessary changes to the manuscript.

06-Oct-2020
Dear Dr Berkenbrock On behalf of the Reviews Editor, I am pleased to inform you that your manuscript entitled "Microfluidic devices for the detection of viruses: aspects of emergency fabrication during the COVID19 pandemic and other outbreaks" has been accepted in its final form for publication in Proceedings A.
COVID-19 rapid publication process: We are taking steps to expedite the publication of research relevant to the pandemic. If you wish, you can opt to have your paper published as soon as it is ready, rather than waiting for it to be published on the scheduled Wednesday. This means your paper will not be included in the weekly media round-up which the Society sends to journalists ahead of publication. However, it will appear in the COVID-19 Publishing Collection which journalists will be directed to each week (https://royalsocietypublishing.org/topic/special-collections/novel-coronavirus-outbreak) If you wish to have your paper published immediately please notify production@royalsociety.org and press@royalsociety.org.
Our Production Office will be in contact with you in due course. You can expect to receive a proof of your article soon. Please contact the office to let us know if you are likely to be away from email in the near future. If you do not notify us and comments are not received within 5 days of sending the proof, we may publish the paper as it stands.
Under the terms of our licence to publish you may post the author generated postprint (ie. your accepted version not the final typeset version) of your manuscript at any time and this can be made freely available. Postprints can be deposited on a personal or institutional website, or a recognised server/repository. Please note however, that the reporting of postprints is subject to a media embargo, and that the status the manuscript should be made clear. Upon publication of the definitive version on the publisher's site, full details and a link should be added.
You can cite the article in advance of publication using its DOI. The DOI will take the form: 10.1098/rspa.XXXX.YYYY, where XXXX and YYYY are the last 8 digits of your manuscript number (eg. if your manuscript number is RSPA-2017-1234 the DOI would be 10.1098/rspa.2017.1234).
For tips on promoting your accepted paper see our blog post: https://royalsociety.org/blog/2020/07/promoting-your-latest-paper-and-tracking-yourresults/ Thank you for your submission. On behalf of the Editors of the journal, we look forward to your continued contributions to the Journal.