Delta Diagnostics strives to make diagnostic test development a fast and inexpensive process. We believe that by doing so, more and better point-of-care tests will reach the market, from which we will all benefit. We realise our vision by making a new platform for rapid test development available. For that, we use sensor technology that has a unique combination of characteristics, making it highly-suitable for test development.
PHOTONIC INTEGRATED CIRCUITS
We make use of integrated photonics, or optical chips. The chips carry wave guides that transport laser light across the chip to many integrated sensors. These sensors are in fact extremely sensitive refractive index sensors.
The binding of biomolecules on the sensor surface leads to a local change in refractive index. By functionalising the sensor with for instance an antibody, a highly sensitive and selective biosensor is obtained.
As the individual sensors are only a few hundred µm in size, many sensors fit on a small chip surface. Each sensor can be functionalised with a different capture molecule, such that many biomarkers can be detected simultaneously even in small sample volumes such as a finger prick blood sample.
An evanescent field extends from the waveguides on the chip surface into the sample and is used to detect changes in refractive index. The refractive index change is proportional to the density of surface-bound biomolecules and can therefore be used to accurately determine the concentration of biomarkers in the sample. Evanescent field sensing is a label-free technology, meaning that a detection label is not needed. This results in faster assays that require less reagents, which is beneficial for rapid diagnostic tests.
LOW-COST TEST DEVELOPMENT
In addition, binding kinetics can be monitored in real-time. This helps tremendously to limit the diagnostic test development time. For instance, it allows you to rapidly and effectively select high-affinity antibodies for your assays. The test development time is further reduced by the fact that the same chip is used for assay development and for the final point-of-care test: once our assay works in the lab it also works at point-of-care.
We developed small and low-cost read-out technology that interfaces with the disposable biosensor chips for read-out and analysis. This technology is used in our test development platform as well as in our point-of-care analyser.