Just had a look at the university website:
quote:
The CD itself can be thought of as a petri dish - the substance that is added interferes and ”scatters’ the CD content introducing a new way of analysing it. The analog laser light interference pattern is then converted into a digital signal from the changes in voltage with this process all occurring in a matter of seconds.
The next step for the research, according to Jones, is standardising the hardware and software behind the myriad of CD and DVD drive models available, as well as testing other sensitive biological or chemical agents that have been used in bioterrorism.
Also,
This goes into it in more detail. Finally,
here is a paper on the topic.
quote:
A CD-based biosensor device for quantitative determination of the differential Gram stain has been developed using consumer-grade hardware, and does not require a light microscope for analysis. The method has been tested against five strains of bacteria, against larger yeast cells, and against an image template that could be printed directly onto CD in different
colours.
An equation has been developed and applied to help in bacterial classification by relating properties of mechanical drive performance with nanoscale bit level data comparisons. The cells act like nonlinear photonic filters, and IR-light scattering through the
deposits under rotation acts like a spectral map for spatial properties of the biological population.