Lab-on-a-chip multiplexed electrochemical sensor enables simultaneous detection of SARS-CoV-2 RNA and host antibodies

The current COVID-19 pandemic highlights the continued need for rapid, accurate, and cost-effective point-of-care (POC) diagnostics that can accurately assess an individual’s infection and immunity status for SARS-CoV-2. As the virus continues to spread and vaccines become more widely available, detecting viral RNA and serological biomarkers can provide critical insights into the status of infectious, previously infectious, and vaccinated individuals over time. Here, we describe an integrated, low-cost, 3D printed, lab-on-a-chip device that extracts, concentrates, and amplifies viral RNA from unprocessed patient saliva and simultaneously detects RNA and multiple host anti-SARS-CoV-2 antibodies via multiplexed electrochemical (EC) outputs in two hours. The EC sensor platform enables single-molecule CRISPR/Cas-based molecular detection of SARS-CoV-2 viral RNA as well as serological detection of antibodies against the three immunodominant SARS-CoV-2 viral antigens. This study demonstrates that microfluidic EC sensors can enable multiplexed POC diagnostics that perform on par with traditional laboratory-based techniques, enabling cheaper and more widespread monitoring of infection and immunity over time. ### Competing Interest Statement HDP, PJ, JJC, DEI are inventors on patents describing the CRISPR EC sensing technology. PJ and DEI are listed as inventors on patents describing the EC sensor platform. EC sensor platform technology has been licensed to GBS Inc. for COVID-19 diagnostics and StataDX, Inc.; PJ and DEI hold equity in StataDx and DEI is a board member. JJC and DRW are co-founders and directors of Sherlock Biosciences. All other authors declare no competing interests. ### Funding Statement This work was supported by the Wyss Institute for Biologically Inspired Engineering at Harvard University and the Paul G. Allen Frontiers Group. J.R. was funded through the UK Natural Environment Research Council (NERC) GW4 FRESH CDT. H.D.P. was supported by the Harvard University Center for AIDS Research (CFAR), an NIH-funded program (P30 AI060354), which is supported by the following NIH co-funding and participating Institutes and Centers: NIAID, NCI, NICHD, NIDCR, NHLBI, NIDA, NIMH, NIA, NIDDK, NINR, NIMHD, FIC, and OAR. M.Y. acknowledges Fonds de recherche du Quebec nature et technologie (FRQNT) postdoctoral fellowship #260284. The MGH/MassCPR COVID biorepository was supported by a gift from Ms. Enid Schwartz, by the Mark and Lisa Schwartz Foundation, the Massachusetts Consortium for Pathogen Readiness, and the Ragon Institute of MGH, MIT and Harvard. ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes The details of the IRB/oversight body that provided approval or exemption for the research described are given below: De-identified clinical saliva samples from the Dominican Republic were obtained from Boca Biolistics under their ethical approvals. RT-qPCR was performed by Boca Biolistics using the Perkin Elmer New Coronavirus Nucleic Acid Detection kit. De-identified clinical plasma samples were obtained from the Crimson Biomaterials Collection Core Facility at Partners Healthcare (currently Mass General Brigham). Additional de-identified clinical plasma and saliva samples were obtained through the Massachusetts Consortium on Pathogen Readiness (MassCPR) and had been collected by Prof. Jonathan Li and Prof. Xu Yu. Additional pre-SARS-CoV-2 pandemic samples were obtained from the Walt Laboratory at Brigham and Women s Hospital. The Institutional Review Board at the MGH, MGB, and Harvard University as well as the Harvard Committee on Microbiological Safety approved the use of the clinical samples in this study. I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines and uploaded the relevant EQUATOR Network research reporting checklist(s) and other pertinent material as supplementary files, if applicable. Yes All data needed to evaluate the conclusions of this work can be found in the paper and/or the Supplementary Materials.