新型碳基纳米复合物的制备及其作为纳米酶在生物传感及成像中的应用

Metal/metal oxide nanoparticles have attracted researchers’ enormous interest due to their intrinsic peroxidase-like activities. Compared with natural enzymes, Metal/metal oxide nanoparticles are advantageous in several aspects, such as low cost, ease of mass production, robustness to harsh environments, and so on. Therefore, these nanozymes have been utilized for sensing, imaging and therapeutics. However, the prosperous applications of peroxidase-like metal/metal oxide nanoparticles are frequently impeded due to their ease of dissolution and agglomeration, which results in the degradation of their catalytic activity. As for the aims of this project, green synthesis of carbon dots was conducted through a solid phase thermal/ hydrothermal treatment approach using small molecules, agricultural waste, and plants. Subsequently, carbon dots-based composite materials were facially prepared in one-pot manner by the addition of metal ions in as-prepared carbon dots solution without requirement of other agents followed by the hydrothermal treatment. The controlled synthesis conditions of carbon based nanocomposites with good stability and strong catalytic activity were proposed after comparison and analysis of the as-prepared carbon based nanocomposites’ structure and performance. On these basis, a series of novel sensing were constructed for discrimination of isomer, disease markers, enzyme activity, and analysis of cell targeting specific chemiluminescence imaging. The implementation of this project will promote the cross and integration of the analytical chemistry, materials science, molecular biology, and medicine. What more, it provides a new platform for the discrimination of isomers and biological active substances as well as the early diagnosis of cancer cells,It is of great significance in promoting the development of analytical chemistry, materials science and biomedicine.

金属或金属氧化物纳米材料具有辣根过氧化物酶的活性，引起广大研究者的普遍关注。与天然酶相比，金属或金属氧化物纳米材料具有合成成本低、易大量合成和耐环境能力强等优点，被广泛地应用于生物传感、成像和治疗等方面。但其不稳定易于聚集，且催化活性低，限制了其应用。本项目拟以有机小分子、农业废弃物和植物为原料制备具有期望性能碳基量子点，以制备的碳基量子点为稳定剂、还原剂，构建绿色、方便地合成碳基纳米复合物的方法；探讨稳定性好、催化活性强的碳基纳米复合物可控合成条件。在此基础上，构建新型生物传感器用于同分异构体、疾病生物标志物、生物酶活性的检测和癌细胞化学发光成像分析。本项目的实施将有利于分析化学、材料科学、分子生物学、医学等相关学科的交叉集成，为同分异构体、生物活性物质检测及癌细胞的早期诊断提供一种新的平台，对分析化学、材料科学和医学的发展具有重要意义。

近红外碳点荧光探针和比例荧光探针因可有效地消除外部干扰而备受关注。掺杂或表面钝化可有效调控碳点的光学和电子属性，使其在传感和成像领域的应用更具优势。基于此，项目开展的研究工作如下：.（1）绿色合成了生物质碳点（C-BQDs和BQDs）。这些生物质碳点展现出近红外发射，并分别选择性响应Hg2+和γ-谷氨酰转肽酶（GGT）。基于光诱导无辐射电子转移引发荧光猝灭机理，建立了基于C-BQD荧光探针用于高选择性检测血清和细胞内的Hg2+。利用内滤效应，建立了基于BQD荧光探针用于高灵敏检测GGT及细胞内GGT成像分析。这些方法简便、灵敏度高、选择性好，使其在传感和成像领域的应用更具优势。.（2）通过掺杂合成了具有优异荧光属性的掺杂碳点（Cu-CDs和N,S-CDs），基于内滤效应，构建了基于Cu-CDs比例荧光探针用于高灵敏检测H2O2，检测限低至5.0nM。基于官能团异构，建立了基于近红外N,S-CDs比例荧光探针用于高灵敏检测Zn2+，检测极限为5.0nM。构建的荧光探针应用于环境样品、生物样品中H2O2、Zn2+检测及细胞成像分析。.（3）合成了具有催化活性的金属掺杂碳点（Cu-CDs和Ce-CDs）。基于内滤效果，构建了基于Cu-CDs的荧光探针用于可视化识别苯二胺同分异构体。基于H2O2介导的氧化反应，构建了基于Ce-CDs的荧光探针用于识别氨基苯酚同分异构体和高选择性检测邻氨基苯酚和间氨基苯酚，检测限分别为0.033μM。该方法成功应用于环境样品的分析。为同分异构体的识别提供了新思路。.（4）合成了掺杂碳点及复合物（Cu(II)/CuO/N-GQDs和Cu-CDs），它们在较宽pH和温度范围内展现优异的过氧化物酶活性。基于H2O2-鲁米诺体系，建立了基于Cu(II)/CuO/N-GQDs和Cu-CDs的化学发光传感分别用于检测尿酸和葡萄糖，且检测限分别为0.041μM和0.32μM，血清样本中尿酸和葡萄糖的加标回收率为85.0％～121.3％。为疾病标志物检测及其临床诊断提供了新方法。.（5）利用T7外切酶辅助，建立了基于信号放大辅助微流控芯片电泳化学发光法检测端粒酶方法，该方法实现端粒酶在单细胞水平分析并成功应用于Hela等细胞裂解液样品分析。为药物筛选、疾病早期诊断提供了新技术。