The unconventional use of matte black nail polish could speed up lab-on-a-chip disease diagnosis. (Credit: BYU)

Electrical engineering students have stumbled upon a very unconventional method that could speed up lab-on-a-chip disease diagnosis.

When someone goes to the hospital for a serious illness, if a bacterial infection is suspected, it can take up to three days to get results from a bacteria culture test. By then, it is often too late to adequately treat the infection, especially if the bacteria are resistant to common antibiotics.

BYU students are working on a project to diagnose antibiotic resistant bacteria, or superbugs, in less than an hour. Their method relies on extracting bacteria from a blood sample and then pulling DNA from that bacteria. If specific genetic codes indicating antibiotic resistance are present in the DNA, fluorescent molecules can be attached to these sites. Laser light can then be shined on the DNA samples and the molecules will light up.

The required precision of aligning the laser light to miniscule DNA samples is complex and leaves little room for error. The research team is working to find effective ways to channel light and DNA containing fluids together in a lab-on-a-chip. The process has been challenging, but they have finally found an unlikely solution — black nail polish.

The nail polish creates a dark film over the chip that absorbs and scatters light to produce a “blackout” layer. This blackout layer blocks out light over most of the chip’s area but allows it to pass through miniscule openings aligned to fluid containing channels. With the presence of the blackout layer, a large beam of laser light can be shined onto the chip with crude alignment tolerances and laser energy only reaches the critical spots that lead to DNA identification.

The matte nail polish makes this process of testing for diseases more accessible and practical in an instrument that could be used in a real hospital setting. The nail polish technique is flexible and can be used on a variety of surfaces.