However, so far no standard scientifically grounded guidelines are available specifying the precise color of light, irradiation power and duration. These parameters need to be optimized, considering that phototherapy is not free of side effects. To enable this, scientists require better ways to measure bilirubin levels, which is exactly what the new study in Physical Chemistry Chemical Physics has contributed to.

In as many as 8 in 10 preterm babies, the liver is unable to cope with bilirubin—a toxic product of red blood cell decay. This leads to elevated bilirubin levels in the blood and the tell-tale yellowish skin color.

Newborn jaundice therapy usually involves exposing the baby to blue light. This transforms the bilirubin molecules so that they can be eliminated by the body bypassing the biochemical reaction that is disrupted in a sick infant's liver.

However, there are no standard guidelines for how long blue light exposure should last, what the optimal irradiation power is, and how it all relates to disease severity.

To resolve this uncertainty, researchers need a way to measure bilirubin concentrations in the tissue more accurately than is now possible. Skoltech scientists suggest supplementing the currently used technique, which detects how much of the incident light is absorbed by the solution, with fluorescence measurements.