Carbon Dots Created From Orange Juice

Orange juice is more than just a good source of vitamin C. It’s also a good source of CDs, or carbon dots, which are nanobits of carbon with unusual properties. Chemists report they can make highly photoluminescent CD nanoparticles via a one-step hydrothermal treatment of orange juice (Chem. Commun., DOI: 10.1039/c2cc33796g). The team, led by Sasmita Mohapatra of the National Institute of Technology, in Rourkela, India, heated pulp-free orange juice to 120 °C for two-and-a-half hours. During this process, they believe, the major constituents of the juice—sucrose, glucose, fructose, citric acid, and ascorbic acid—undergo hydrothermal carbonization to form CDs that are between 1.5 and 4.5 nm in diameter and have carboxylic acid groups distributed across their surfaces. The CDs are separated from other particles via centrifugation. As much as 400 mg of CDs can be obtained from just 40 mL of juice. Mohapatra’s team showed that the juice-derived dots have high photostability and low toxicity, making them good candidates for cellular imaging probes.