A fiber optic sensor holds promise for noninvasive monitoring of early stage embryos during the in vitro fertilization (IVF) process. The sensor concurrently measures hydrogen peroxide and pH in solution, and consists of a single optical fiber, the tip of which was functionalized with a reactive fluorescent coating. Researchers from the Australian Research Council's Centre for Nanoscale BioPhotonics (CNBP) and the University of Adelaide believe the sensor has the potential to be used across a range of biological applications, but that it is particularly well suited to the IVF industry. "Unregulated production of hydrogen peroxide by an embryo, as well as fluctuating levels of pH, can indicate embryonic stress, impacting embryo development," said doctoral student Malcom Purdey. "Our state-of-the-art sensor is a single strand of optical fiber that is completely noninvasive. It could be placed right next to the embryo, causing no disruption to its development, monitoring critical stages of the IVF process." Researcher Malcolm Purdey synthesizes fluorescent sensors. Courtesy of the Centre for Nanoscale BioPhontonics. Current clinical examinations of such embryos are solely visually based, the researchers said, and even recent prototype sensors require a complicated setup involving multiple fibers, detectors and light sources. The single-fiber dual sensor could monitor multiple embryonic parameters objectively with a single piece of technology, allowing better understanding of the dynamic processes taking place at earliest stage of life. The sensor also has the potential for broader application as well. "Hydrogen peroxide is an indicator of cell stress and possible illness," Purdey said. "In the future, our sensor could be used inside of the body, to examine cells in the arteries to look for evidence of vascular disease. It could also be used to aid cancer detection, too." The research was published in the journal Sensors (doi: 10.3390/s151229893 [open access]).