Technology overview
Stratophase’s unique SpectroSens technology is an optical microchip sensor which measures chemical processes and detects biological targets. The SpectroSens sensor is capable of detecting all classes of biological targets, including proteins, viruses and bacteria, on the same microchip.
A SpectroSens sensor measures the change in the refractive index of a liquid as it passes across the surface of the optical chip with a precision better than one part in one million. It directly measures chemical substances and detects the presence of biological entities in the liquid, using antibodies attached to the sensor surface. It produces simultaneous multiple discrete readings to provide more reliable measurement and detection.
Stratophase’s patented and practical measurement and detection technology is built on proven science from telecoms, optics and biotech. It uses its own unique and patented direct writing technology to manufacture the optical microchips, producing a robust and practical sensor.
SpectroSens in detail
Stratophase’s patented technology detects toxins, viruses and bacteria in real time by measuring very precisely the change in the refractive index of a liquid as it passes across the surface of the SpectroSens microchip.
The untreated surface of the optical silicon chip can measure chemicals. However, when it is pre-treated with antibodies it also becomes sensitive to biological substances. In use, light is transmitted via a small fibre-optic cable to a Bragg grating within the chip, while target agents or contaminants are carried in liquid across the sensor surface.
The grating then reflects a precisely-defined colour, or wavelength, of light which is determined by the refractive index of the liquid in the sensing window. When target agents are contained in the liquid they bind to the antibodies on the sensor surface causing tiny changes in refractive index. These can be detected by very precise and continuous monitoring of the wavelength of light reflected from the sensor.
The reflected light travels back along the optical cable to the readout unit which accurately measures the wavelength of the reflected light and therefore the refractive index of the liquid or particles bound to the surface.
Each chip can contain many sensor areas. The liquid under test is selectively brought to these individual sensor areas using a fluidic system. This enables each chip to take multiple measurements using a single readout unit.
SpectroSens advantages
The SpectroSens optical microchip offers a number of advantages for commercial use over other technologies:
- detects all classes of biological targets, including proteins, viruses and bacteria, regardless of size, on the same microchip.
- detects minute changes in refractive index for process control.
- use of fibre optics enables a network of multiple sensing points across many kilometres all linked to a single readout unit.
- immune to electro-magnetic interference.
- safe for flammable environments. SpectroSens is an optical device without electrical power and therefore is not a potential source of ignition.
- measures biological targets directly, removing the need for expensive fluorescent tagging.
- high sensitivity makes it suitable for critical environments.
- provides simultaneous multiple discrete readings which gives more reliable measurement and detection, as well as reducing false positives.
- inexpensive manufacture through its simple concept.
- small, robust chip makes it suitable for hand-held operation.
SpectroSens components
SpectroSens detection systems comprise the microchips and readout units. There are a number of choices to suit biological detection or process refractive index measurement, either on-line or off-line.
For biological detection, the microchip is housed in a disposable plastic package that simply plugs directly into the readout unit. To enable these chips to detect biological particles, antibodies are attached to the surface of the detector chip. When viruses, bacteria or proteins bind to the antibodies, the refractive index changes and their presence is accurately measured and identified.
Disposable biological detection chip package
For refractive index measurement in a process line, the microchip is packaged in a standard pipe fitting. Multiple detector heads can be connected via optical fibre to a single remote readout unit. As the microchips and cables are solely optical, this makes them ideal for use in flammable environments or where there is electromagnetic interference.
Microchip packaged in standard pipe fitting for on-line measurement
The readout unit comprises all the electronics necessary in a standard rack mount or bench-top case. Hand-held units will be available shortly.
Bench-top readout unit