Qi Lu, Berlind Vosberg, Zhenyu Wang, Priyadharshini Balasubramanian, Maabur Sow, Carla Volkert, Raul Gonzalez Brouwer, Ingo Lieberwirth, Robert Graf, Fedor Jelezko, Martin B Plenio, Yingke Wu, Tanja Weil
Defect centers in a nanodiamond (ND) allow the detection of tiny magnetic fields in their direct surroundings, rendering them as an emerging tool for nanoscale sensing applications. Eumelanin, an abundant pigment, plays an important role in biology and material science. Here, for the first time, we evaluate the comproportionation reaction in eumelanin by detecting and quantifying semiquinone radicals through the nitrogen-vacancy color center. A thin layer of eumelanin is polymerized on the surface of nanodiamonds (NDs), and depending on the environmental conditions, such as the local pH value, near-infrared, and ultraviolet light irradiation, the radicals form and react in situ...
March 12, 2024: Journal of the American Chemical Society