Drug-Derived Bright and Color-Tunable N-Doped Carbon Dots for Cell Imaging and Sensitive Detection of Fe3+ in Living Cells

Inspired by the diverse drug compounds with various heteroatoms (such as N, S, and P) in the drug library, facile synthesis of a new kind of bright and color-tunable N-doped carbon dots (NCDs) has been reported by using a popular antibiotic-aminosalicylic acid-as precursor. The N doping of CDs not only enable great improvement of photoluminescence (PL) efficiency and tunability of PL emission, but also enrich surface functional groups to broaden its application. The as-prepared NCDs possess tunable PL and show a quantum yield of 16.4%, which is the result of PL improvement effect of introduced nitrogen atoms among CDs. The cellular toxicity on H1299 cancer cells indicates that the NCDs have negligible cytotoxicity, excellent biocompatibility, and great resistance to photobleaching. Moreover, the drug-derived NCDs showed excellent sensitivity in detection of Fe³⁺ in living cells, which indicates the potential application in diagnosis and related biological study.