Enhancement of Labeled Alpha-fetoprotein Antibodies and Antigen-antibody Complexes Fluorescence with Silver Nanocolloids

• Published in: Procedia engineering Vol. 140; pp. 57 - 66
• Main Authors: Vaschenko, Svetlana, Ramanenka, Andrey, Kulakovich, Olga, Muravitskaya, Alina, Guzatov, Dmitry, Lunevich, Anatoly, Glukhov, Yuri, Gaponenko, Sergey
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 2016
• Subjects: alpha-fetoprotein; immunoassay; plasmon-enhanced fluorescence; poin-of-care testing; silver nanoparticles; plasmon-enhanced fluorescence; alpha-fetoprotein; silver nanoparticles; poin-of-care testing; immunoassay
• ISSN: 1877-7058; 1877-7058
• DOI: 10.1016/j.proeng.2015.08.1111

A model immunoassay test system is proposed based on metal enhanced photoluminescence to analyze low concentrations of alpha-fetoprotein, a tumor marker. Antigen-antibody reaction was performed on polystyrene plates coated with silver nanoparticles to increase sensitivity of fluorescent immunoassay and signal-to-noise ratio as compared to silver-free system. The proposed test system model uses layer-by-layer assembly approach, LED excitation and nanowatt photodetection set-up, so it is characterized by smaller probe volume, fast analysis and simplicity. The proposed model system offers alpha-fetoprotein detection at concentrations used in clinical practice. Photostability and photoluminescence enhancement for labeled alpha-fetoprotein antibodies on a silver substrate were found to depend on antibodies concentration. Labeled antibodies photostability on substrates was found to deviate within 20% as compared to silver-free samples whereas photoluminescence intensity enhancement is typically in the range of 6-8 times.