title: Detection of Hepatitis C core antibody by dual-affinity yeast chimera and smartphone-based electrochemical sensing.
abstract: Yeast cell lines were genetically engineered to display Hepatitis C virus (HCV) core antigen linked to gold binding peptide (GBP) as a dual-affinity biobrick chimera. These multifunctional yeast cells adhere to the gold sensor surface while simultaneously acting as a "renewable" capture reagent for anti-HCV core antibody. This streamlined functionalization and detection strategy removes the need for traditional purification and immobilization techniques. With this biobrick construct, both optical and electrochemical immunoassays were developed. The optical immunoassays demonstrated detection of anti-HCV core antibody down to 12.3pM concentrations while the electrochemical assay demonstrated higher binding constants and dynamic range. The electrochemical format and a custom, low-cost smartphone-based potentiostat ($20 USD) yielded comparable results to assays performed on a state-of-the-art electrochemical workstation. We propose this combination of synthetic biology and scalable, point-of-care sensing has potential to provide low-cost, cutting edge diagnostic capability for many pathogens in a variety of settings.
authors.affiliation: School of Medicine, University of California, San Diego, La Jolla, CA, 92093 USA. Electronic address: earonoffspencer@ucsd.edu.
authors.forename: Eliah
authors.initials: E
authors.lastname: Aronoff-Spencer
authors.affiliation: Department of Electrical and Computer Engineering, University of California, San Diego, La Jolla, CA, 92093 USA.
authors.forename: A G
authors.initials: AG
authors.lastname: Venkatesh
authors.affiliation: Department of Electrical and Computer Engineering, University of California, San Diego, La Jolla, CA, 92093 USA.
authors.forename: Alex
authors.initials: A
authors.lastname: Sun
authors.affiliation: School of Medicine, University of California, San Diego, La Jolla, CA, 92093 USA.
authors.forename: Howard
authors.initials: H
authors.lastname: Brickner
authors.affiliation: School of Medicine, University of California, San Diego, La Jolla, CA, 92093 USA; VA San Diego Healthcare System, San Diego, CA, 92161 USA.
authors.forename: David
authors.initials: D
authors.lastname: Looney
authors.affiliation: Department of Electrical and Computer Engineering, University of California, San Diego, La Jolla, CA, 92093 USA.
authors.forename: Drew A
authors.initials: DA
authors.lastname: Hall
mesh_terms: D001681:Biological Assay / Q000295:instrumentation; D002678:Chimera; D003217:Conductometry / Q000295:instrumentation*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D018937:Hepatitis C Antibodies / Q000097:blood* / Q000276:immunology; D018936:Hepatitis C Antigens / Q000097:blood / Q000276:immunology*; D007118:Immunoassay / Q000295:instrumentation*; D063731:Mobile Applications; D000067716:Point-of-Care Testing; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D000068997:Smartphone; D014584:User-Computer Interface; D015003:Yeasts / Q000235:genetics / Q000821:virology*
chemical_list: D018937:Hepatitis C Antibodies; D018936:Hepatitis C Antigens
keywords: Electrochemical biosensor; Hepatitis C virus; Point-of-care diagnostics; Whole cell biosensor; Yeast biobrick; mHealth