Optical Nanomaterials Lab

Nitrogen-doped carbon dots (CDs) have attracted considerable attention across various research areas and applications due to their enhanced optical properties and photostability. However, the mechanism of nitrogen incorporation in CDs remains elusive, hampering the precise control over nitrogen-incorporated structures and the investigation of the effects of nitrogen on the electronic structure and optical properties of CDs. In this study, we employed a rational design approach, utilizing glucosamine and ethylene glycol as the carbon source and co-reagent, respectively, to synthesize N-doped CDs. Our synthesis strategy involved pinacol rearrangement and iminium ion cyclization reactions, enabling the reliable formation of N-doped CDs. Notably, the resulting CDs exhibited distinctive emissive states attributed to heteroatomic defect structures, including oxygenic and nitrogenic polycyclic aromatic hydrocarbons. To gain further insights into their energy levels and electronic transitions, we conducted comprehensive investigations, employing extended Hückel calculations and pump-probe spectroscopy. The synthesized CDs displayed great promise as bioimaging and photodynamic therapy agents, highlighting their potential for biomedical applications. Moreover, our study significantly contributes valuable insights into the rational design of N-doped CDs with controllable chemical and electronic structures, thereby paving the way for advancements in their diverse range of applications. This work has been published in Nanoscale Advances (IF = 5.598). 

Despite advances in diagnostic and therapeutic methods, the prognosis of patients with hepatocellular carcinoma (HCC) remains poor due to the delay in diagnosis. Herein, we aimed to discover a highly sensitive and specific biomarker for HCC based on genomic big data analysis and create an HCC-targeted imaging probe using carbon nanodots (CNDs) as contrast agents. In genomic analysis, we selected glucose transporter 2 (GLUT2) as a potential imaging target for HCC. We confirmed the target suitability by immunohisto-chemistry tests of 339 patient samples, where 81.1% of the patients exhibited underexpression of GLUT2. To visualize GLUT2, we conjugated CNDs with glucosamine (GLN) as a targeting ligand to yield glucosamine-labeled CNDs (GLN-CNDs). A series of in vitro and in vivo experiments were conducted on GLUT2-modified HepG2 cells to confirm the specificity of the GLN-CNDs. Our results indicate that GLUT2 is a promising target for HCC and that GLN-CNDs may potentially be used as targeted imaging probes for diagnosing HCC. This work has been published in Nanoscale (IF = 8.307).