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

Abstract

There continues to be a great need for rapid, accurate, and cost-effective point-of-care devices that can diagnose the presence of SARS-CoV-2 virus and development of IgG and IgM antibody responses in early and late stages of COVID-19 disease. Here, we describe a versatile multiplexed electrochemical (EC) sensor platform modified with an antifouling nanocomposite coating that enables single-molecule CRISPR/Cas-based molecular detection of SARS-CoV-2 viral RNA with on-chip signal validation as well as multiplexed serological detection of antibodies against three SARS-CoV-2 viral antigens. The CRISPR-based EC platform achieved 100% accuracy for detection of viral RNA and showed an excellent correlation with RT-qPCR using 30 clinical saliva samples. The serology EC platform obtained 100% sensitivity and 100% specificity for anti-SARS-CoV-2 IgG, as well as 94% specificity and 82% sensitivity for anti-SARS-CoV-2 IgM with 112 clinical plasma samples. These data demonstrate that integration of CRISPR-based RNA detection and serological assays with antifouling nanocomposite-based EC sensors enables performance as good or better than traditional laboratory-based techniques.

Highly multiplexed detection of microRNAs, proteins and small molecules using barcoded molecular probes and nanopore sequencing

“…Combining biomarker assays into a multiplexed platform has clear advantages for the application of multi-biomarker approaches 5 . Such strategies have already been attempted in a number of areas including; Alzheimer’s 6, 7 , amyotrophic lateral sclerosis 8 , cardiovascular disease 9, 10, 11 , chronic obstructive pulmonary disease 12 , infection 13 and cancers 14, 15, 16, 17, 18, 19 . Many of the methodologies employed rely upon antibody recognition of an epitope and an associated optical readout for each analyte.…”

Electroanalysis, a Log to Hold on to in Difficult Times

“…Most of the developed (bio)platforms, beyond the required sensitivity and selectivity, have demonstrated reliability for the analysis of the target biomarkers in infected patient biofluids, mainly serum and saliva, and provide results that agree with those obtained with other more accepted and sophisticated methodologies that require more effort, economic investment, knowledge, and application in centralized environments. Among those, the detection of IgG and IgM antibodies against spike (S) and nucleocapsid (N) receptors, the most known and antigenic structural proteins SARS-CoV-2, in serum at a paper-based electrochemical platform functionalized with graphene oxide (GO) [1], the coupling of magnetic beads with carbon black screenprinted electrodes for N or S proteins detection in saliva [2], an ultrasensitive electrochemical biosensor based on isothermal rolling circle amplification (RCA) able to detect as low as 1 copy/μL of N and S genes of SARS-CoV-2 in nasopharyngeal swabs, in less than 2 h [3] and multiplexed platforms based on the use of an antifouling nanocomposite for simultaneous detection of SARS-CoV-2 RNA and S and N-specific antibodies in saliva using CRISPR-based technology and serological assays, respectively [4], or low-cost laser-engraved graphene electrodes able to interrogate in just 10 min biomarkers related with three key aspects of circulating COVID-19 disease in blood and saliva: viral infection, immune response, and disease severity [5] deserve to be highlighted. Therefore, beyond doubt, electroanalysis and electroanalytical devices offer unique and exceptional capabilities in the fight against one of the most dramatic health and economic crises of the modern era, paving the way for the implementation of affordable and easily accessible diagnostic devices for the entire population.…”