Biomedical

Due to unqiue electrical, optical and antimicrobial properties, nanomaterials have been critical in the latest wave of biomedical developments, and are being used in biosensors, drug delivery, and medical imaging.

Biosensors and Chemical Detectors

Criteria for good sensor materials include sensitivity, selectivity, reliability, ease of fabrication and use and low cost. Blue Nano silver nanowires and carbon nanotubes offer advantages in sensitivity due to their high surface-to-volume ratio; generally a very low detection limit is observed using biosensors based on one-dimentional nanomaterials.


Both silver nanowires and carbon nanotubes offer a stabile immobilization of biomolecules while allowing them to retain their activity. For electrochemical biosensors, both silver nanowires and carbon nanotubes offer a functional conductive pathway between biomolecules and the electrode surface. For biosensor using Plasmon resonance, silver nanomaterials are more sensitive than gold ones in detecting small amounts of analyte.

Drug Delivery and Cancer Treatment

Carbon nanotubes have high mechanical strength and a large length to diameter ratio, allowing them to penetrate considerable distances through biological tissues while inflicting little damage or inflammatory response. These properties are currently exploited in "nanosyringe" applications such as transdermal drug delivery (nicotine patches) and respiratory therapies that require the efficient penetration of pulmonary mucous membranes.


Silver nanoparticles have been conjugated with cancer antibodies, and may be able to selectively label cancer cells within the body. These particles absorb certain wavelengths of light (near-infrared, or NIR) that pass through biological tissues and rapidly convert its energy into heat, which may allow the selective destruction of cancer cells.

Medical Imaging

Carbon and silver nanomaterials act as contrast agents and contrast agent carriers for medical imaging modalities. Both carbon and silver absorb NIR light, allowing for their detection by Raman scattering, and fluorescence spectroscopy. A problem with many potential contrast agent materials for magnetic resonance imaging and gamma scintography is that they tend to concentrate in certain parts of the body, and in high concentrations may be toxic. Carbon nanotubes can be linked to these agents to reduce their toxicity and facilitate their excretion, enabling their use in medical imaging applications.