ac400536k_si_001.pdf (3.34 MB)
A Near-Infrared, Surface-Enhanced, Fluorophore-Linked Immunosorbent Assay
journal contribution
posted on 2013-08-06, 00:00 authored by Michael D. Furtaw, David L. Steffens, Teresa M. Urlacher, Jon P. AndersonThe enzyme-linked
immunosorbent assay is commonly used for research
and clinical applications but typically suffers from a limited linear
range and is difficult to multiplex. The fluorophore-linked immunosorbent
assay is a closely related technique with good linear range and the
ability to detect multiple antigens simultaneously but is typically
less sensitive. Here, we demonstrate a near-infrared, surface-enhanced
fluorophore-linked immunosorbent assay with sensitivity comparable
to its enzyme-linked counterpart. A 59-fold enhancement to sensitivity
(slope of linear fit) and an 8-fold improvement in LOD are demonstrated
on a direct assay with rabbit immunoglobulin-G as a model system.
The technique is also tested on a clinically relevant assay to detect
alpha-fetoprotein, in which a 42-fold enhancement to sensitivity is
demonstrated along with a 16-fold improvement in LOD. The technique
enables these accomplishments while maintaining the entire traditional
assay protocol and simply adding two steps at the end. This technique
may prove superior to current protocols for biomarker research and
clinical diagnoses, which require high sensitivity along with quantitation
over an extended range.