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A label‐free photonic crystal biosensor for the assessment of iron status using ferritin
Author(s) -
Peterson Ross David,
Cunningham Brian,
Andrade Juan,
Engeseth Nicki
Publication year - 2013
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.27.1_supplement.845.17
Subject(s) - ferritin , biosensor , detection limit , iron deficiency , biomolecule , serial dilution , antibody , chemistry , materials science , chromatography , biochemistry , medicine , immunology , pathology , alternative medicine , anemia
Identification of populations at risk of iron deficiency is of critical concern. We present an application of photonic crystal (PC) biosensors as a diagnostic test for ferritin, a biomarker for iron deficiency. PCs are periodic dielectric surface structures designed to reflect a narrow band of wavelengths when illuminated by a broadband light source. Adsorption of biomolecules causes the reflected wavelength to shift to greater values, providing a simple mechanism for label‐free detection using available detection instruments. PC surface was functionalized with silane for immobilization of primary ferritin antibodies, followed by a blocking step to inactivate remnant silane binding sites. Sensitivity was tested using serial dilutions of human liver ferritin (450 kDa) from 5.0 to 0.15 μg/ml; and a secondary antibody to amplify initial signal. Specificity of the assay was verified by evaluating biosensor binding to BSA. The PC sensor gave a concentration‐dependent response for ferritin (R2= 0.986). When compared to commercial ELISA kit, ferritin response provided comparable limits of detection. Antibodies showed high specificity to ferritin. A 40‐minute assay protocol for label‐free detection of ferritin provided dose‐dependent response in the physiologically relevant concentration range for ferritin in serum; a step towards a simple point‐of‐care assay for iron deficiency diagnosis. Grant Funding Source : College of ACES DNS 20/20