“A host of other human health, animal health, and environmental needs could be addressed by point-of-care testing,” notes Keith Page, CEO of Argento Diagnostics. “However, achieving true portability while maintaining quality on par with a large clinical laboratory remains a challenge. A diagnostic system in field situations must accept a variety of common sample sources, often with poor quality.”
Argento’s platform technology can be compacted to the size of a typical smart phone. The touch-screen interface requires minimal technical savvy, and the data can be transmitted via Internet. Miniaturization of Argento’s technology is made possible by a novel detection method that amplifies the signal 106 times.
According to the company, its electrochemical immunoassay system is capable of detecting 30 viral particles in 1 mL of nasal lavage. Argento utilizes a familiar immunoassay with the analyte captured on antibody-coated magnetic beads.
The complexes are detected by silver nanoparticles composed of 106 silver ions coated with a specific binding molecule. The unique attribute of this technology comes from the detection of silver ions by anodic stripping voltammetry. This method involves coating the silver particles with ammonium isothiocyanite that attributes a negative charge to the particles.
The coated particles are drawn to the positively charged electrodes on the assay chips, where the particles are dispersed into silver ions. The number of silver ions is directly proportional to the number of complexes.
Argento’s technology eliminates the need for harsh oxidative chemicals used to generate silver ions. The system can utilize copper, gold, and silver detection systems in a multiplex reaction with a common sample entry point. The time for analysis depends on the viscosity of the sample. An assay based on saliva takes about three to five minutes, Page says.
“The use of proteins for diagnostic tests is typically limited by the detection methods, which are only sensitive enough when the protein concentrations have already reached critical thresholds and disease has progressed. Our current detection capabilities are on par with clinical labs, and the detection could be improved further depending on a clinical need.”