Development of a smartphone-based biosensor device for detecting sars-cov-2 antigens in body fluids using localized surface plasmon resonance (lspr)

A method comprising:

• illuminating a metal surface of a nanostructure-based LSPR (localized surface plasmon resonance) biosensor directly or using an optical fiber with a monochromatic, broadband, or laser light;
• measuring a reference intensity of absorbed, reflected, transmitted or scattered light from the nanostructure-based LSPR biosensor;
• applying a linker molecule or polymer chain or nucleic acid (DNA, RNA) or peptide strand or capture antibody or polydopamine or alkane thiol or synthetic molecules with varying carbon chains comprised of —NH2 or —COOH or —SH group at one end or both ends of the molecules to the metal nanostructure LSPR biosensor;
• applying an intermediate layer comprised of polyethylene glycol (PEG) or streptavidin or avidin or biotin or Polyethylenimine (PEI) or polyaziridine or dextran to the linker molecule;
• applying probe antibodies or primary antibodies and/or secondary antibodies to the intermediate layer;
• applying a body fluid sample comprised of saliva, blood, sweat, tear, or cerebrospinal fluid to a metal surface of the nanostructure-based LSPR biosensor with linker, intermediate, and capture/probe antibodies;
• illuminating the metal surface of the nanostructure-based LSPR biosensor with the monochromatic, broadband, or laser light;
• measuring an intensity of absorbed, reflected, transmitted, or scattered light from the nanostructure-based LSPR biosensor having the body fluid sample and comparing the measured intensity with the reference intensity;
• detecting a spectral shift of the absorbed, reflected, transmitted, or scattered light from the nanostructure-based LSPR biosensor having the body fluid sample;
• and
• signaling that the body fluid sample is positive for a presence of a particular biomaterial in response to detecting the spectral shift of the absorbed, reflected, transmitted, or scattered light, wherein the biomaterial has binded or adsorbed to the metal surface of the nanostructure-based LSPR biosensor.