Any engineered structure with a monomeric unit in size range of 1-100 nm is considered a nanomaterial. Macroscopic materials with nano-scale surface features and microscopic particles in the nano-size range are thus included.
Fremont, CA: Nano-based therapeutics and diagnostic systems have been increasingly being used in a variety of fields of medicine as sensors, immunostimulants, delivery vehicles, radiation sensitizers, and viral inhibitors. The application of nanomaterials in the diagnosis, prevention, and treatment of viral diseases is reviewed in detail in a paper recently published in the journal Pharmaceutics, highlighting areas of significant progress or stagnation over the last few decades.
Nanomaterials in Diagnosis
Any engineered structure with a monomeric unit in size range of 1-100 nm is considered a nanomaterial. Macroscopic materials with nano-scale surface features and microscopic particles in the nano-size range are thus included.
Carbon nanotubes are hollow cylindrical structures with intriguing electric properties that allow for their use in biosensors through the incorporation of a specific protein or nucleic acid probes. Conjugation with complementary DNA or RNA to the virus being detected, for example, results in a high-speed virus sensor with a very low detection limit, where variations in current through the sensor can be used to infer viral load. Because of their lower degree of curvature, flat graphene sheets of carbon can also be bound with antibodies or DNA to create sensors that can interact with larger biomolecules than carbon nanotubes.
Surface plasmon resonance is a phenomenon that occurs when gold nanoparticles exhibit unique light interactions that lead to intense adsorption across a narrow range of wavelengths. The wavelength of light that is most strongly absorbed by the particles is determined by particle shape and size and can be tuned from visible to near-infrared.
Because near-infrared light penetrates biological tissue the best, sensors that rely on optical signaling in this range are ideal as a diagnostic platform. As with carbon nanotubes, relevant complementary molecules can be attached to the particles, causing them to only bind with the virus or antibody under study.
Likewise, proximity to other particles can impact the specific wavelength of light in resonance with the particles. The presence of a compound of interest can thus be decided colorimetrically by inducing inter-particle bonding. Many lateral flow severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) detection assays rely on the use of gold nanoparticles, which combine with viral RNA in the sample to generate a visible red line.
