DiscSPR turns ordinary Blu-ray, DVD, and CD discs into sensor chips. The grooves already built into these discs can help create an SPR signal, which means the expensive nanostructured chip in a traditional sensor can be replaced with something cheap and mass-produced.
Regeneron ISEF Awardee
Lockheed Martin
Water Environment Association of Texas
Office of Naval Research
Stockholm Junior Water Prize
Howmet Aerospace FoundationDiscSPR turns the microscopic grooves already built into optical discs into the grating for a low-cost SPR sensor.
Blu-ray, DVD, and CD-R discs already contain nanoscale grooves manufactured at massive scale for data storage — the same kind of precision pattern a lab-made diffraction grating would otherwise need.
A working SPR sensor needs a nanostructured chip, and that chip is usually the expensive, slow-to-fabricate part. When every measurement depends on a costly custom surface, testing stays occasional, centralized, and far from where the water actually is.
Specialized hardware and custom sensing surfaces can make frequent local measurements harder to sustain.
SPR sensors measure how light behaves at a thin metal surface. When the liquid touching that surface changes, the reflected light shifts. DiscSPR uses the grooves in optical discs to help create and read that shift.
The widest spacing of the three discs tested. CD-R chips gave the highest sensitivity measured in this project, 394 nm per refractive index unit.
The build was kept simple: prepare the disc chip, coat it with metal, place it into a small holder, and pass liquids over the sensing surface while measuring the reflected light.
The disc-based chips produced measurable SPR responses. Silver coatings gave cleaner signals than copper, and front-side illumination worked better than shining light through the disc.
DiscSPR shows that commercial discs can be turned into low-cost SPR chips. To become a practical water-quality device, the platform needs selective chemistry and real-water testing.
1. Add selectivity. Attach receptors that respond to one target pollutant instead of any refractive-index change.
2. Test real samples. Compare tap, lake, and groundwater samples against known concentrations.
3. Shrink the readout. Move from a lab-style optical setup toward a portable version.
The website gives the short version. Step through the original presentation below for the full experimental story, figures, and progression of the project.
