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BioAstral: Innovative Hyperspectal Detector Technology for high resolution microscopy, microarrays and single molecule biomedical applications

BioAstral innovation enables advanced space-science imaging technology to address biomedical research needs.
A super-conducting tunnel junction (STJ or Josephson Junction) device, used to capture light from distant galaxies, has been developed as an instrument for biological research. The work has been carried out with our partners the University of Leicester and the European Space Agency.

A most valuable and immediate application of the invention is in quantitative, multi-colour detection of molecules imaged by microscopy, and the detection of fluorescent probes hybridized to cell components or to microarrays, which are used in the discovery and testing of new drugs. However, we already have developments in train to expand our IP position. This will enable future development and growth by targeting other markets.

BioAstral Ltd has acquired seed financing with the intention of securing more to fund the first phase of commercialization. BioAstral aims to set the global standard for high-end detectors used in sensitive microscopes and readout systems.

Cryogenic STJ Detector Capabilities


Fluorescence emission spectra of five fluorochomes used in biology, on a common array substrate, detected by our prototype STJ system; peak to left is infrared.

The exquisite sensitivity can be exploited through:

Greatly increased quantification of signals from biological assays
The use of multiple fluorochromes simultaneously
Higher throughput
Orders more linearity.

Because of the minute instrument background, the signal-to-noise improvement over any other detector means it has a six to eight order linear response, compared to two or three for CCD and photomultiplier detectors.

More details of the detector technology are on the ESA website here.

Our STJ cryogenic detector is 1000 times more powerful at detecting fluorescence in biological assays than current technology, and it is unique in giving the colours of photons arriving without resort to filters, gratings or other spectroscopy. An international patent application has been filed to protect the Intellectual Property.

BioAstral Makes News

A press release describing the early stages of the invention - Gene Genius from Space Science - was published by the UK Particle Physics and Astronomy Research Council, PPARC.

For an excellent summary of our technology and why it is needed by biologists, please see the article in 'Genomics and Proteomics' by Hank Hogan, linked by clicking on the title below:

Genomics and Proteomics: If Only We Could Make Every Photon Talk
By seeking to make every photon tell a tale, instrument makers are on the verge of providing genomics and proteomics researchers a tool to tease out more of nature's secrets. Hyperspectral imagers allow the use of multiple, overlapping fluorochromes and can remove sources of noise. By Hank Hogan

An introduction is also published here: http://www.spaceref.com/news/viewpr.html?pid=12951

Related projects

The STJ cryogenic photon detection technology has been developed with the European Space Agency Technology Centre (ESTEC). They have many STJ publications describing the technology and its applications in astronomy and astrophysics.

STJ technology is also being applied to mass spectrometry, where it can detect time-of-flight and size of the particles in MALDI-TOF instrumentations. Publications describing this applicating from Lawrence Livermore National Laboratories and DoE laboratories in the US, Switzerland (commercial instrument: Macromizer from Comet, and their information described the STJ detection for ion impact determination; Google 'Macromizer comet Malditof' of see http://dx.doi.org/10.1021/ac0482054 for scientific paper) and Germany.

Why Not CCDs?

The band gap of silicon - used to make CCDs - is very nearly 1 eV. The STJ we use is made of tantalum. The energy gap of tantalum is very nearly 0.001 eV

Single optical photons are at the limit for detection in a silicon detector of any kind, unless there an internal amplification stage, as in an Avalanche photodiode, to boost the 1 electron to more than 30 (the noise of the internal preamplifier). There is no amplification stage in an STJ.

Even with amplification, a CCD detector cannot measure the energy (colour) of the incident light directly, since every optical photon gives a starting signal of one or at most two electrons. One optical photon gives a thousand or more electrons in an STJ, the number being proportional to the energy (wavelength) of the incoming single photon.

Even with cooling, the CCD will have thermal dark current as background, while the STJ will not, as it is operated well below the superconductor transition temperature. In fact, the STJ will essentially (we have proved this experimentally) be noiseless.