Heteroatom doping of carbon dots (CDs) can efficiently tune the structure of electronic energy levels and modulate the photochemical properties of CDs. However, the reported synthesis routes of heteroatom-doped CDs are complicated and rigorous. Herein, a simple and rapid low-temperature heating strategy was applied to synthesize fluorescent nitrogen and phosphorus dual-doped CDs (N,P-CDs) using sucrose as carbon source, and 1,2-ethylenediamine (EDA) and phosphoric acid as dopants, respectively. These N,P-CDs exhibit excellent fluorescent stability over wide pH range solutions (4–11), ultrahigh ion strength (3 M KCl), and longtime UV light irradiation (3 h continuously), which makes these N,P-QDs promising good candidates for fluorescent probes. These N,P-CDs showed excellent biocompatibility, multicolor cellular imaging, and non-cytotoxicity to human hepatocellular carcinoma HepG2 cells even at 500 μg/mL levels for 48 h incubation. These N,P-CDs exhibited a strong blue emission and a sensitive response to hemoglobin. The N,P-CDs based fluorescent probe was then applied to sensitively determine hemoglobin with a detection limit of 0.29 nM. Notably, it was also applied for label-free detection of hemoglobin in human urine samples and human blood samples, which indicated its potential applications in clinical diagnosis and other biologically related study.

碳点（CD）的杂原子掺杂可以有效地调节电子能级的结构并调节CD的光化学性质。然而，所报道的杂原子掺杂的CD的合成路线是复杂而严格的。本文以蔗糖为碳源，以1,2-乙二胺（EDA）和磷酸为掺杂剂，采用简单快速的低温加热策略合成了荧光氮，磷双掺杂CD（N，P-CD）。 ， 分别。这些N，P-CD在宽pH范围溶液（4-11），超高离子强度（3 M KCl）和长时间UV光照射（连续3 h）方面均具有出色的荧光稳定性，这使这些N，P-QD成为有希望的荧光探针的良好候选者。这些N，P-CD表现出出色的生物相容性，多色细胞成像，即使在500μg/ mL水平下孵育48小时，对人肝癌HepG2细胞也没有细胞毒性。这些N，P-CDs表现出强烈的蓝色发射和对血红蛋白的敏感反应。然后将基于N，P-CDs的荧光探针应用于检测极限为0.29 nM的血红蛋白。值得注意的是，它还用于无标记检测人尿液和人血样品中的血红蛋白，这表明其在临床诊断和其他生物学相关研究中的潜在应用。