Bhunia Susanta Kumar, Pradhan Nibedita, Jana Nikhil R
Centre for Advanced Materials, Indian Association for the Cultivation of Science , Kolkata 700032, India.
ACS Appl Mater Interfaces. 2014 May 28;6(10):7672-9. doi: 10.1021/am500964d. Epub 2014 Apr 15.
A carbon-based fluorescent nanoparticle is considered to be a new generation nontoxic nanoprobe suitable for various bioimaging and sensing applications. However, the synthesis of such a high-quality nanoparticle is challenging, and its application potential is mostly unexplored. Here we report a vitamin B1 carbonization-based approach for blue and green fluorescent carbon nanoparticles of <10 nm size with a fluorescence quantum of up to 76%. We found that carbonization of vitamin B1 in the presence of phosphate salt at ∼90-130 °C for about 2 h produces highly fluorescent carbon nanoparticles of 1-6 nm size. The particle size and fluorescence property can be controlled by varying the reaction temperature and nature of phosphate salt. Elemental analysis shows the incorporation of a large percentage (up to 48 wt %) of other elements (such as nitrogen, oxygen, phophorus, and sulfur) in the carbon matrix. The chemical structure of vitamin B1 (thiamine) is unique in a sense that it consists of a large number of heteroatoms along with unsaturated bonds and offers low-temperature carbonization with the formation of a nanoparticle having an optimum ratio of sp(2) and sp(3) carbon atoms. These carbon nanoparticles have high colloidal stability and stable fluorescence and have been used as fluorescent imaging probes.
碳基荧光纳米颗粒被认为是一种适用于各种生物成像和传感应用的新一代无毒纳米探针。然而，合成如此高质量的纳米颗粒具有挑战性，并且其应用潜力大多尚未得到探索。在此，我们报告了一种基于维生素B1碳化的方法，用于制备尺寸小于10 nm、荧光量子产率高达76%的蓝色和绿色荧光碳纳米颗粒。我们发现，维生素B1在磷酸盐存在下于约90 - 130 °C碳化约2小时，可产生尺寸为1 - 6 nm的高荧光碳纳米颗粒。颗粒尺寸和荧光性质可通过改变反应温度和磷酸盐的性质来控制。元素分析表明，碳基质中掺入了大量（高达48 wt%）的其他元素（如氮、氧、磷和硫）。维生素B1（硫胺素）的化学结构独特，因为它由大量杂原子以及不饱和键组成，并能在低温碳化时形成具有最佳sp(2)和sp(3)碳原子比例的纳米颗粒。这些碳纳米颗粒具有高胶体稳定性和稳定的荧光，并已用作荧光成像探针。
