Colorimetric dosimeter to promote most efficient use of neonatal phototherapy.

Abstract

tHyperbilirubinemia is a systemic global problem and an often diagnosed pathology in newborns. In mostcases, blue-light phototherapy (410–460 nm) is the only treatment required to prevent the bilirubinneurotoxicity, but its effectiveness is dose-dependent and is highly affected by the skills, knowledge,and attention of nurses and clinicians who implement the treatment. This paper presents a novellight-sensitive colorimetric dosimeter to simulate the effect of blue-light phototherapy on the opticalproperties of in vitro bilirubin. The dosimeter is based on a multilayered organic structure comprisinga light-stable green-light emitter (copper phthalocyanine, C32Cl16CuN8), and a blue-light-sensitive redemitter (poly{[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylene]vinylene}, OC1OC6-PPV). The optical andchemical properties of the dosimeter were investigated by fluorescence and FTIR spectroscopies and bycolor coordinates of CIE (1931) diagram chromatics, while the photochemical processing of bilirubin wasevaluated by UV–vis absorption spectroscopy. The optical response of the dosimeter under conventional(10 W/cm2) and intensive (40 W/cm2) phototherapy was found to present the same photochemicalkinetics as bilirubin. These findings highlight a cutting-edge solution for monitoring bilirubin eliminationin neonates as a function of the dosimeter’s color evolution. This novel colorimetric dosimeter providesa standardized method of reporting and measuring phototherapy dose to promote an efficient use ofavailable phototherapy units in health facilities.