基于单原子纳米酶的比色免疫传感体系可视化检测蛋白类肿瘤标志物

Tumor biomarker proteins can reflect the occurrence and development of many kinds of cancers. Detection of their levels is a promising indicator for diagnosis of various cancers. Single-atom nanozymes (SAzymes) have become one of the leading areas and hot topics on the nanomaterials science due to the excellent catalytic activity. In this project, we intend to synthesize novel SAzymes through the spatial confinement strategy by using transition metal involved metal-organic framework (MOFs) as the precursor. It will possess both structural advantage of MOFs and excellent catalytic activity, high stability and good water solubility. For the first time, antibodies are labeled with SAzymes and SAzyme-based colorimetric immunoassay platforms are constructed. As a result, high selective identification and sensitive visualization of tumor biomarker proteins can be realized benefitting from the high specificity of immunoreaction and the high sensitivity of SAzyme-catalyzed chromogenic reactions. The catalytic mechanism and structure-activity relationship of SAzymes will be disclosed from the aspects of reaction dynamics, single-atom catalytic sites and radicals, etc. by means of spectral measurements, structural characterizations and theory calculations. Meanwhile, the construction and detection mechanism of the sensor platforms will be investigated and revealed in detail through the physicochemical methods. This project follows closely the recent development of the relevant disciplines and is unique. It may fill some technology gaps of the application of MOFs and SAzymes in the field of analytical chemistry, and provide the theoretical support for developing novel clinical method to detect tumor biomarkers.

蛋白类肿瘤标志物能反映多种肿瘤的发生、发展，其检测已成为各种癌症诊断的很有潜力的指标。单原子纳米酶（SAzymes）具有极优异的催化性能，是纳米科学的前沿热点之一。本项目拟以过渡金属-有机骨架材料（MOFs）为前驱体，通过空间限域策略合成兼具高催化性能和MOFs的结构优势，且稳定性高、水溶性好的新型SAzymes；并首次以SAzymes标记抗体构建比色免疫分析传感体系，利用免疫反应的专一选择性和SAzymes催化显色反应的高灵敏度，实现蛋白类肿瘤标志物的特异性识别与可视化检测。此外，借助光谱测量、结构表征和理论计算等从反应动力学、单原子活性位点、自由基等角度解析SAzymes的催化机理及构效关系；利用光谱学、热力学、理论计算等手段系统阐明传感体系的构建和传感机理，优化检测性能。本项目既能丰富MOFs和SAzymes在分析化学领域的实际应用，又能为拓展肿瘤标志物的临床检测方法提供理论支持。

蛋白类肿瘤标志物能反映多种肿瘤的发生、发展，其检测已成为各种癌症诊断的很有潜力的指标。单原子纳米酶（SAzymes）具有极优异的催化性能，是纳米科学的前沿热点之一。在本项目中，我们主要以金属-有机骨架材料（MOFs）为前驱体合成了各类具有优异氧化酶或过氧化酶活性的SAzymes，在多角度解析SAzymes催化机理的基础上开发了系列比色传感体系，实现了对蛋白类疾病标志物等生物分子的特异性识别与可视化检测。具体包括：通过高温碳化血晶素掺杂ZIF-8获得具有类过氧化物酶活性的系列Fe单原子纳米酶，结合抗坏血酸调控的催化显色反应，构建了相关蛋白的比色检测方法；通过简便的溶剂热法一步合成具有类过氧化物酶活性的各种过渡金属-氮-碳材料（f-MMN），并利用催化性能最优的f-FeNC构建二酶和三酶级联反应体系，实现了对葡萄糖、α-葡糖苷酶的灵敏检测以及筛选α-葡糖苷酶抑制剂作为抗糖尿病和抗病毒药物；采用主客体策略合成了具有极高类氧化酶活性的Pd单原子纳米酶，通过理论与实验相结合的手段系统探究了其催化机理和活性位点，在用于酸性磷酸酶含量的测定的基础上设计了NAND比色逻辑门，进一步拓展了纳米酶的应用；以乙酰丙酮铂的ZIF-8为前驱体合成了具有氧化酶活性的Pt SAzymes，结合熊果苷水解反应，用于α-葡糖苷酶检测及其抑制剂筛选；合成了具有类过氧化物酶活性的Ru SAzymes，基于巯基化合物的金属位点屏蔽效应，构建了乙酰胆碱酯酶及其抑制剂的检测方法；等。本项目既能丰富SAzymes在分析化学领域的实际应用，又能为拓展肿瘤等疾病标志物的临床检测方法提供理论支持。