Wang Shipeng, Zhao Haoran, Yang Jinliang, Dong Yahui, Guo Shaozheng, Cheng Qian, Li Yu, Liu Shouxin
Key Laboratory of Bio-Based Material Science & Technology (Ministry of Education), College of Material Science and Engineering, Northeast Forestry University, Harbin 150040, P. R. China.
College of Chemistry and Chemical Engineering, Shaoxing University, Shaoxing, Zhejiang 312000, China.
ACS Omega. 2023 Feb 10;8(7):6550-6558. doi: 10.1021/acsomega.2c06942. eCollection 2023 Feb 21.
Multicolor fluorescent carbon dots (CDs) have received widespread attention due to their excellent fluorescence performance and promising prospects in anti-counterfeiting and sensing detection. To date, most of the multicolor CDs synthesized are derived from chemical reagents; however, the overuse of chemical reagents during the synthesis process will pollute the environment and limit their application. Herein, multicolor fluorescent biomass CDs (BCDs) were prepared by a one-pot ecofriendly solvothermal method, with spinach as the raw material based on solvent control. The as-obtained BCDs can emit blue, crimson, grayish white, and red luminescence, and their quantum yields (QYs) are 8.9, 12.3, 10.8, and 14.4%, respectively. The results of the characterization of BCDs reveal that the regulating mechanism for multicolor luminescence is mainly ascribed to the change of the boiling point and polarity of solvents, which changes the carbonization process of polysaccharides and chlorophyll in spinach, resulting in the altered particle size, surface functional groups, and porphyrin luminescence properties. Further research reveals that blue BCDs (BCD1) show an excellent sensitive and selective response to Cr(VI) in a concentration scale of 0-220 μM with a detection limit (LOD) of 0.242 μM. More importantly, the intraday and interday relative standard deviation (RSD) values were less than 2.99%. The recovery rate of the Cr(VI) sensor for tap water and river water is 101.52-107.51%, which indicates that the sensor has the advantages of high sensitivity, selectivity, rapidity, and reproducibility. Consequently, different multicolor patterns are obtained by using the obtained four BCDs as fluorescent inks, which exhibit beautiful landscape and advanced anti-counterfeiting effects. This study provides a low-cost and facile green synthesis strategy for multicolor luminescent BCDs and proves that BCDs have broad application prospects in ion detection and advanced anti-counterfeiting.
多色荧光碳点（CDs）因其优异的荧光性能以及在防伪和传感检测方面的广阔前景而受到广泛关注。迄今为止，大多数合成的多色CDs都来源于化学试剂；然而，合成过程中化学试剂的过度使用会污染环境并限制其应用。在此，以菠菜为原料，基于溶剂控制，通过一锅法环保溶剂热法制备了多色荧光生物质碳点（BCDs）。所制备的BCDs可发出蓝色、深红色、灰白色和红色荧光，其量子产率（QYs）分别为8.9%、12.3%、10.8%和14.4%。BCDs的表征结果表明，多色发光的调控机制主要归因于溶剂沸点和极性的变化，这改变了菠菜中多糖和叶绿素的碳化过程，导致粒径、表面官能团和卟啉发光性质发生改变。进一步研究表明，蓝色BCDs（BCD1）在0 - 220 μM浓度范围内对Cr(VI)表现出优异的灵敏和选择性响应，检测限（LOD）为0.242 μM。更重要的是，日内和日间相对标准偏差（RSD）值均小于2.99%。Cr(VI)传感器对自来水和河水的回收率为101.52 - 107.51%，这表明该传感器具有高灵敏度、选择性、快速性和重现性等优点。因此，将所制备的四种BCDs用作荧光油墨可获得不同的多色图案，呈现出美丽的景观和先进的防伪效果。本研究为多色发光BCDs提供了一种低成本且简便的绿色合成策略，并证明了BCDs在离子检测和先进防伪方面具有广阔的应用前景。
