氮化碳红色荧光量子点的可控制备及其在可视化传感与多模态生物成像中的应用研究

Graphitic carbon nitride quantum dots (g-C3N4 QDs) have received extensive attention in the areas of sensing, imaging and therapy, due to their excellent photoelectric properties and favorable biocompatibility. However, the reported g-C3N4 QDs prefer to show inhomogeneous particle sizes and lack study on the regulation and mechanism of red fluorescence and multimodality bioimaging. This project aims to synthesis homogeneous sized, well-structured yet red fluorescent Eu-g-C3N4 QDs by using F127 template-based method. Fabricating visual fluorescence sensing methods and portable test paper. Using Eu, I and Gd as the co-doping agents, developing multimodality bioimaging applications based on g-C3N4 QDs. This project will explore both synthesis and fluorescence red-shift mechanism of the Eu-g-C3N4 QDs, yet solve the over-thermal polymerization issue during the synthesis of g-C3N4 QDs. The project finding will provide guidance on the fabrication of homogeneous red fluorescent g-C3N4 nanomaterials and promote their application in visual fluorescence sensing and multimodality bioimaging. In addition, it will develop a rapid and convenient service of fluorescence, CT and MRI multimodality bioimaging techniques in medical diagnostic tests.

石墨相氮化碳量子点（g-C3N4 QDs）因具有优异的光电性质与生物相容性在化学传感、生物成像和癌症治疗领域备受关注。然而，尺寸均一性低、缺乏红色荧光发光及多模态生物成像功能是阻碍g-C3N4 QDs广泛应用的关键难题。对此，本项目拟以F127模板法，制备尺寸均匀、结构稳定且可发射红色荧光的Eu-g-C3N4 QDs，构筑基于Eu-g-C3N4 QDs的可视化荧光传感方法，开发便携式荧光检测试纸；通过Eu、I和Gd元素共掺杂，建立基于g-C3N4 QDs的多模态生物成像应用。旨在从理论层面上研究Eu-g-C3N4 QDs的生长及荧光红移的机制，从技术层面上解决g-C3N4 QDs高温合成过程中过度热聚合的问题。项目预期研究成果为制备尺寸均匀、发射红色荧光氮化碳纳米材料及其多模态生物成像应用提供实验和理论指导, 并促进荧光、CT及MRI多模态生物成像技术在医疗检测领域的快速、便捷化使用。

石墨相氮化碳量子点（g-C3N4 QDs）因具有优异的光电性质在化学传感、生物成像和癌症治疗等领域备受关注。然而，尺寸均一性低、缺乏红色荧光发光及多模态生物成像功能是阻碍g-C3N4 QDs广泛应用的关键难题。本项目研究了F127模板法及超声剥离水热法，制备了尺寸相对均匀、结构稳定、水溶性好且可发射绿色及橙色荧光的Eu-g-C3N4纳米材料。研究结果表明选择空间位阻较大的原料可实现Eu的体相掺杂，使Eu取代了部分C的位置，破坏了三嗪环结构中的部分C-N和C=N键，从而实现Eu-g-C3N4荧光的红移。随后，我们构筑了基于Eu-g-C3N4纳米材料对炭疽杆菌孢子标志物2,6-吡啶二羧酸和四环素的可视化荧光传感方法，并实现了对DPA的荧光生物成像检测。结合智能手机拾色软件和自制的Eu-g-C3N4荧光检测试纸，实现了对2,6-吡啶二羧酸和四环素的简单、快速、实时、便捷的多通道、高通量可视化检测方法。通过Eu、I和Gd元素共掺杂，制备了发射蓝色荧光及展现出纵向弛豫性质的(Eu, I, Gd)-g-C3N4纳米材料。本研究从理论层面上研究了Eu-g-C3N4纳米材料的生长及其荧光红移的机制，从技术层面上解决了对比度基于Eu-g-C3N4纳米材料的显著可视化实时、便捷、快速传感。项目的研究成果为制备尺寸均匀、发射红色荧光氮化碳纳米材料提供了实验和理论指导, 并促进其在荧光生物成像技术在医疗检测领域的快速、便捷化使用。