Who said CDs were dead, this is, hands down, the coolest paper on screening techniques I have seen in a while. I haven’t seen the rest of the paper, not Open Access, of course, but the abstract does make it sound cool.
“High-density competitive indirect microimmunoassays were performed in both sides of compact discs by direct absorption of immunoreagents on polycarbonate surface, using gold- or enzyme-labeled immunoglobulins as tracers for displaying the immunoreaction. The operational principle is based on the use of a low-reflectivity compact disc as analytical platform that allows the reflection/transmission (30/70%) of the CD reader laser beam ( 780 nm). The reflected light is used to scan the disc track keeping it in movement. The transmitted light is detected by a planar photodiode integrated on the CD drive. The variation of the optical transmission of the light caused by the immunoreaction products is related to the sample concentration. As a proof of concept, low abundant compounds, commonly used as pesticides, were detected in a 60-min total assay time, with a limit of detection ranging from 0.02 to 0.62 ug/L for 2,4,5-TP, chlorpyriphos, and metolachlor. The obtained results show the enormous prospective of compact discs in combination with CD players for multiresidue and drug discovery applications.”
Why are techniques like these important in the world of environmental analysis? Because they change the paradigm from laboratory based techniques to field based analysis. You don’t have to take a bunch of samples, spend a lot of time and money shipping them to a lab and waiting for the results. You can pop your samples into a CD player and one hour later (less than a 74 minute listening time on a CD!), you’ll have results.
Awesome stuff, I’d love to see it in action, or even try to replicate the work. It looks like you have to make some modifications to the player to make it work, but hey, there are millions of CD players that are going to be obsoleted in the next few years.