title: Polyelectrolyte-coated gold magnetic nanoparticles for immunoassay development: toward point of care diagnostics for syphilis screening.
abstract: Immediate response for disease control relies on simple, inexpensive, and sensitive diagnostic tests, highly sought after for timely and accurate test of various diseases, including infectious diseases. Composite Fe3O4/Au nanoparticles have attracted considerable interest in diagnostic applications due to their unique physical and chemical properties. Here, we developed a simple coating procedure for gold magnetic nanoparticles (GMNs) with poly(acrylic acid) (PAA). PAA-coated GMNs (PGMNs) were stable and monodispersed and characterized by Fourier transform-infrared spectroscopy (FT-IR), transmission electron microscopy, UV-visible scanning spectrophotometry, thermogravimetric analysis, and Zetasizer methodologies. For diagnostic application, we established a novel lateral flow immunoassay (LFIA) strip test system where recombinant Treponema pallidum antigens (r-Tp) were conjugated with PGMNs to construct a particle probe for detection of anti-Tp antibodies. Intriguingly, the particle probes specifically identified Tp antibodies with a detection limitation as low as 1 national clinical unit/mL (NCU/mL). An ample pool of 1020 sera samples from three independent hospitals were obtained to assess our PGMNs-based LFIA strips, which exhibited substantially high values of sensitivity and specificity for all clinical tests (higher than 97%) and, therefore, proved to be a suitable approach for syphilis screening at a point-of-care test manner.
authors.affiliation: College of Chemistry and Chemical Engineering, Shaanxi University of Science and Technology, Xi'an 710021, China.
authors.forename: Dong
authors.initials: D
authors.lastname: Yang
authors.forename: Jianzhong
authors.initials: J
authors.lastname: Ma
authors.forename: Qinlu
authors.initials: Q
authors.lastname: Zhang
authors.forename: Ningning
authors.initials: N
authors.lastname: Li
authors.forename: Jiangcun
authors.initials: J
authors.lastname: Yang
authors.forename: Paul Ananda
authors.initials: PA
authors.lastname: Raju
authors.forename: Mingli
authors.initials: M
authors.lastname: Peng
authors.forename: Yanling
authors.initials: Y
authors.lastname: Luo
authors.forename: Wenli
authors.initials: W
authors.lastname: Hui
authors.forename: Chao
authors.initials: C
authors.lastname: Chen
authors.forename: Yali
authors.initials: Y
authors.lastname: Cui
mesh_terms: D006046:Gold; D007118:Immunoassay / Q000379:methods; D008403:Mass Screening / Q000379:methods; D053768:Metal Nanoparticles; D019095:Point-of-Care Systems; D011108:Polymers; D013587:Syphilis / Q000097:blood* / Q000175:diagnosis*
chemical_list: D011108:Polymers; D006046:Gold