title: DNA-Directed Antibody Immobilization for Enhanced Detection of Single Viral Pathogens.
abstract: Here, we describe the use of DNA-conjugated antibodies for rapid and sensitive detection of whole viruses using a single-particle interferometric reflectance imaging sensor (SP-IRIS), a simple, label-free biosensor capable of imaging individual nanoparticles. First, we characterize the elevation of the antibodies conjugated to a DNA sequence on a three-dimensional (3-D) polymeric surface using a fluorescence axial localization technique, spectral self-interference fluorescence microscopy (SSFM). Our results indicate that using DNA linkers results in significant elevation of the antibodies on the 3-D polymeric surface. We subsequently show the specific detection of pseudotyped vesicular stomatitis virus (VSV) as a model virus on SP-IRIS platform. We demonstrate that DNA-conjugated antibodies improve the capture efficiency by achieving the maximal virus capture for an antibody density as low as 0.72 ng/mm(2), whereas for unmodified antibody, the optimal virus capture requires six times greater antibody density on the sensor surface. We also show that using DNA conjugated anti-EBOV GP (Ebola virus glycoprotein) improves the sensitivity of EBOV-GP carrying VSV detection compared to directly immobilized antibodies. Furthermore, utilizing a DNA surface for conversion to an antibody array offers an easier manufacturing process by replacing the antibody printing step with DNA printing. The DNA-directed immobilization technique also has the added advantages of programmable sensor surface generation based on the need and resistance to high temperatures required for microfluidic device fabrication. These capabilities improve the existing SP-IRIS technology, resulting in a more robust and versatile platform, ideal for point-of-care diagnostics applications.
authors.affiliation: Department of Biomedical Engineering, Boston University , Boston, Massachusetts 02215, United States.
authors.forename: Elif
authors.initials: E
authors.lastname: Seymour
authors.affiliation: Department of Electrical and Computer Engineering, Boston University , Boston, Massachusetts 02215, United States.
authors.forename: George G
authors.initials: GG
authors.lastname: Daaboul
authors.affiliation: Department of Biomedical Engineering, Boston University , Boston, Massachusetts 02215, United States.
authors.forename: Xirui
authors.initials: X
authors.lastname: Zhang
authors.affiliation: Department of Mechanical Engineering, Boston University , Boston, Massachusetts 02215, United States.
authors.forename: Steven M
authors.initials: SM
authors.lastname: Scherr
authors.affiliation: Department of Biomedical Engineering, Boston University , Boston, Massachusetts 02215, United States.|School of Medicine, Bahcesehir University , Istanbul 34730, Turkey.
authors.forename: Nese Lortlar
authors.initials: NL
authors.lastname: Ünlü
authors.affiliation: Department of Microbiology, Boston University School of Medicine , Boston, Massachusetts 02218, United States.
authors.forename: John H
authors.initials: JH
authors.lastname: Connor
authors.affiliation: Department of Biomedical Engineering, Boston University , Boston, Massachusetts 02215, United States.|Department of Electrical and Computer Engineering, Boston University , Boston, Massachusetts 02215, United States.
authors.forename: M Selim
authors.initials: MS
authors.lastname: Ünlü
mesh_terms: D055910:Antibodies, Immobilized / Q000737:chemistry*; D015374:Biosensing Techniques / Q000295:instrumentation; D004247:DNA / Q000737:chemistry*; D015342:DNA Probes / Q000737:chemistry*; D008856:Microscopy, Fluorescence / Q000295:instrumentation; D018116:Vesiculovirus / Q000302:isolation & purification* / Q000472:pathogenicity
chemical_list: D055910:Antibodies, Immobilized; D015342:DNA Probes; D004247:DNA