A cancer and serious disease-detecting biomedical probe that can be made from the juice of rancid oranges

"tiny probe that uses fluorescence to signal cells' pH in terms of their acidity or alkalinity – it detects whether cells are at risk, or in the early stages of cancer or other serious diseases.... nanobiosensor, which measures only one-billionth of a metre, is made of fluorescent carbon dots that can be created from food waste,... increased temperature and pressure inside the reactor break down the initial molecular structure of the ingredients, helping them form a new material: carbon dots"