title: A comparison of nanoparticle-antibody conjugation strategies in sandwich immunoassays.
abstract: Point-of-care (POC) diagnostics such as lateral flow and dipstick immunoassays use gold nanoparticle (NP)-antibody conjugates for visual readout. We investigated the effects of NP conjugation, surface chemistries, and antibody immobilization methods on dipstick performance. We compared orientational, covalent conjugation, electrostatic adsorption, and a commercial conjugation kit for dipstick assays to detect dengue virus NS1 protein. Assay performance depended significantly on their conjugate properties. We also tested arrangements of multiple test lines within strips. Results show that orientational, covalent conjugation with PEG shield could improve NS1 detection. These approaches can be used to optimize immunochromatographic detection for a range of biomarkers.
authors.affiliation: a Winchester Engineering and Analytical Center , U.S. Food and Drug Administration , Winchester , Massachusetts.
authors.forename: Justina O
authors.initials: JO
authors.lastname: Tam
authors.affiliation: b Department of Mechanical Engineering , Massachusetts Institute of Technology , Cambridge , Massachusetts.
authors.forename: Helena
authors.initials: H
authors.lastname: de Puig
authors.affiliation: a Winchester Engineering and Analytical Center , U.S. Food and Drug Administration , Winchester , Massachusetts.|c Institute for Medical Engineering and Science, Massachusetts Institute of Technology , Cambridge , Massachusetts.
authors.forename: Chun-Wan
authors.initials: CW
authors.lastname: Yen
authors.affiliation: c Institute for Medical Engineering and Science, Massachusetts Institute of Technology , Cambridge , Massachusetts.
authors.forename: Irene
authors.initials: I
authors.lastname: Bosch
authors.affiliation: d MIT Little Devices Lab and the MIT-SUTD International Design Centre , Massachusetts Institute of Technology , Cambridge , Massachusetts.
authors.forename: Jose
authors.initials: J
authors.lastname: Gómez-Márquez
authors.affiliation: a Winchester Engineering and Analytical Center , U.S. Food and Drug Administration , Winchester , Massachusetts.
authors.forename: Charles
authors.initials: C
authors.lastname: Clavet
authors.affiliation: b Department of Mechanical Engineering , Massachusetts Institute of Technology , Cambridge , Massachusetts.|e Department of Engineering , University of Massachusetts Boston , Boston , Massachusetts.
authors.forename: Kimberly
authors.identifier: http://orcid.org/0000-0002-4839-3179
authors.initials: K
authors.lastname: Hamad-Schifferli
authors.affiliation: c Institute for Medical Engineering and Science, Massachusetts Institute of Technology , Cambridge , Massachusetts.|f Department of Microbiology and Immunobiology , Harvard Medical School , Boston , Massachusetts.
authors.forename: Lee
authors.identifier: http://orcid.org/0000-0002-9387-8212
authors.initials: L
authors.lastname: Gehrke
mesh_terms: D000906:Antibodies / Q000737:chemistry* / Q000276:immunology*; D006046:Gold / Q000737:chemistry; D006801:Humans; D007118:Immunoassay / Q000379:methods*; D053768:Metal Nanoparticles / Q000737:chemistry*; D017361:Viral Nonstructural Proteins / Q000032:analysis* / Q000276:immunology
chemical_list: D000906:Antibodies; C079340:NS1 protein, Dengue virus type 2; D017361:Viral Nonstructural Proteins; D006046:Gold
keywords: bioconjugation; dengue; dipstick; lateral flow; nanoparticle; rapid test