A Biocompatible Fluorescent Ink Based on Water‐Soluble Luminescent Carbon Nanodots

C-dots on hand: Luminescent carbon nanodots were synthesized and were shown to be biocompatible, have low toxicity, and distinctive photoluminescence properties. These C-dots are inexpensive to synthesize and could potentially be used for versatile applications, such as anticounterfeiting, information encryption, and information storage. Detailed facts of importance to specialist readers are published as ”Supporting Information”. Such documents are peer-reviewed, but not copy-edited or typeset. They are made available as submitted by the authors. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.