title: Detection of Hepatitis B virus antigen from human blood: SERS immunoassay in a microfluidic system.
abstract: A highly sensitive immunoassay utilizing surface-enhanced Raman scattering (SERS) has been developed with a new Raman reporter and a unique SERS-active substrate incorporated into a microfluidic device. An appropriately designed Raman reporter, basic fuchsin (FC), gives strong SERS enhancement and has the ability to bind both the antibody and gold nanostructures. The fuchsin-labeled immuno-Au nanoflowers can form a sandwich structure with the antigen and the antibody immobilized on the SERS-active substrate based on Au-Ag coated GaN. Our experimental results indicate that this SERS-active substrate with its strong surface-enhancement factor, high stability and reproducibility plays a crucial role in improving the efficiency of SERS immunoassay. This SERS assay was applied to the detection of Hepatitis B virus antigen (HBsAg) in human blood plasma. A calibration curve was obtained by plotting the intensity of SERS signal of FC band at 1178cm(-1) versus the concentration of antigen. The low detection limit for Hepatitis B virus antigen was estimated to be 0.01IU/mL. The average relative standard deviation (RSD) of this method is less than 10%. This SERS immunoassay gives exact results over a broad linear range, reflecting clinically relevant HBsAg concentrations. It also exhibits high biological specificity for the detection of Hepatitis B virus antigen.
authors.affiliation: Institute of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224 Warsaw, Poland.
authors.forename: Agnieszka
authors.initials: A
authors.lastname: Kamińska
authors.affiliation: Institute of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224 Warsaw, Poland.
authors.forename: Evelin
authors.initials: E
authors.lastname: Witkowska
authors.affiliation: Institute of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224 Warsaw, Poland.
authors.forename: Katarzyna
authors.initials: K
authors.lastname: Winkler
authors.affiliation: Institute of High Pressure Physics, Polish Academy of Sciences, Sokołowska 29/37, 01-142 Warsaw, Poland.
authors.forename: Igor
authors.initials: I
authors.lastname: Dzięcielewski
authors.affiliation: Institute of High Pressure Physics, Polish Academy of Sciences, Sokołowska 29/37, 01-142 Warsaw, Poland.
authors.forename: Jan L
authors.initials: JL
authors.lastname: Weyher
authors.affiliation: Institute of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224 Warsaw, Poland.
authors.forename: Jacek
authors.initials: J
authors.lastname: Waluk
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation* / Q000706:statistics & numerical data; D006046:Gold; D006511:Hepatitis B Antigens / Q000097:blood*; D006514:Hepatitis B Surface Antigens / Q000097:blood; D006515:Hepatitis B virus / Q000276:immunology; D006801:Humans; D007118:Immunoassay / Q000295:instrumentation* / Q000706:statistics & numerical data; D053768:Metal Nanoparticles; D046210:Microfluidic Analytical Techniques / Q000295:instrumentation* / Q000706:statistics & numerical data; D013059:Spectrum Analysis, Raman / Q000379:methods*
chemical_list: D006511:Hepatitis B Antigens; D006514:Hepatitis B Surface Antigens; D006046:Gold
keywords: Basic fuchsin; Hepatitis B virus; Immunoassays; Microfluidics; Surface-enhanced Raman spectroscopy (SERS)