纳米酶作为一种有酶学催化功能的纳米材料，拥有一些天然酶无法比拟的优点，如多样可定制性、制备简单、低成本，高稳定性和易回收重复利用等，在化学传感、医学诊断和环境保护等领域展示出广阔的应用前景。美中不足的是催化效率尚有待提高。
近年来，以金属离子为中心离子，有机小分子为配体分子合成的金属有机框架材料（Metal Organic Frameworks-MOFs），因孔隙率高、比表面积大和丰富的金属活性位点，广泛应用于催化、分离、存储和分子识别等领域，并逐渐拓展到纳米酶的研究中。MOFs纳米酶在某种程度上模拟了天然酶的结构，近年来逐渐成为纳米酶研究的重点。遗憾的是，MOFs纳米酶的溶解性差，限制了与催化底物分子的有效结合，导致催化活性不高；另一方面，催化反应条件对催化活性的影响，尤其是缓冲体系对催化活性的影响，尚缺乏深入的分析。基于此，本论文从模仿天然结构出发，以提高MOFs的类酶催化活性问题为切入点，选择铜离子和铁离子分别作为中心离子合成MOFs纳米酶，具体研究内容和研究成果如下：
1.  通过Cu2+与腺嘌呤（A）的配位，合成了克量级且水溶性极好的Cu-A纳米片。作为漆酶模拟酶，以2，4-二氯苯酚为底物分子研究Cu-A纳米酶的催化活性，结果发现在pH = 7的三种缓冲体系中，呈现出完全不同的催化活性：在10 mM Tris-HAc中表现出优异的催化性能，相较于天然漆酶，活性提高了10倍以上；在10 mM MES（4-吗啉乙烷磺酸）中活性大幅降低（相较于Tris中的10.2 %），在10 mM HEPES （N -2-羟乙基哌嗪- N '-2-乙烷磺酸）（pH = 7, 25 ℃）中活性进一步降低（相较于Tris中的9.4 %）。在此基础上，对催化活性的差异进行了解析。另外，随着NaCl浓度由0 mM逐渐增加到500 mM，催化活性逐渐增强。利用Km (Michaelis常数)和Vmax(最大速率值)解释了缓冲种类/NaCl浓度依赖性的催化活性。
2.  基于Cu-A漆酶模拟酶对2，4-二氯苯酚的催化性能，以4-氨基安替比林（4-AP）为显色底物分子，实现了对2，4-二氯苯酚的高灵敏检测。但是，Cu-A漆酶模拟酶可以催化多种酚类（2，4-二氯苯酚、邻氯苯酚、间氯苯酚、对氯苯酚、邻氯苯酚、对氯苯酚、苯酚和邻苯二酚），无法实现对多种酚类的同时检测。基于此设计了一种以三种缓冲溶液为传感通道的比色传感器阵列，同时鉴别了低至10 μM的2，4-二氯苯酚， 邻氯苯酚，间氯苯酚，对氯苯酚，苯酚和邻苯二酚，甚至可以定量2，4-二氯苯酚（作为模型分析）。通过准确识别二元和三元混合物，甚至18个盲样中：含有六种酚中的一种或是三元混合物中的一种，进一步验证了该性能。最后，将所设计的传感器阵列成功应用于各种模拟水样和实际水样中，实现对6种具有代表性的酚类物质的识别，为不同水样中酚类物质的检测提供了广阔的应用前景。
3. 以Fe3+为中心离子，氨基对苯二甲酸为配体分子，合成了Fe-MIL-88B-NH2。作为一种氧化酶，以TMB为底物分子，没有催化活性。当分别与20种氨基酸孵育后，只有加入组氨酸对TMB呈现出催化氧化活性。在解析催化活性变化的基础上，实现了对组氨酸的特异性检测。

As a kind of nanomaterials with enzymatic catalytic function, nanozymes have some incomparable advantages of natural enzymes, such as diverse customizability, simple preparation, low cost, high stability and easy recycling and reuse. It shows broad application prospects in the fields of medical diagnosis and environmental protection. The fly in the ointment is that the catalytic efficiency has yet to be improved.
In recent years, metal organic frameworks (Metal Organic Frameworks), synthesized with metal ions as central ions and organic ligand molecules as ligands, are widely used in catalysis, separation, Storage and molecular recognition and other fields, and gradually expanded to the research of nanozymes. MOFs nanozymes mimic the structure of natural enzymes to some extent, and have gradually become the focus of nanozyme research in recent years. Unfortunately, the poor solubility of MOFs nanozymes limits the effective binding with catalytic substrate molecules, resulting in low catalytic activity; on the other hand, the effect of catalytic reaction conditions on catalytic activity, especially the effect of buffer system on catalytic activity, there is still a lack of in-depth analysis. Based on this, starting from imitating the natural structure, this paper starts with the problem of improving the enzyme-like catalytic activity of MOFs, and selects copper ions and iron ions as the central ions to synthesize MOFs nanozymes. The specific research contents and research results are as follows:
1. Herein, through Cu2+ coordinating with adenine (A), Cu-adenine nanosheets with excellent water solubility in gram scale were synthesized. As a laccase mimic, Cu-Adenine exhibits excellent catalytic performance in 10 mM Tris-HAc (More than ten times that of natural laccase), and greatly decreases in 10 mM MES (4-morpholine ethanesulfonic acid) (compared to 10.2 % in Tris) and further decreases in 10 mM HEPES (N-2-hydroxyethyl piperazine-N'-2-ethanesulfonic acid) (compared to 9.4 % in Tris) (pH = 7, 25 oC). Moreover, upon gradually increasing NaCl from 0 to 500 mM, the catalytic activity further enhances. Such the buffer species/NaCl concentration-dependent catalytic activity is explained with the help of Km (Michaelis constant) and Vmax (maximum rate value) 
2. Based on the catalytic performance of Cu-A laccase-mimicking enzyme for 2,4-dichlorophenol, 4-aminoantipyrine (4-AP) was used as the chromogenic substrate to realize a highly sensitive detection of 2,4-dichlorophenol. However, Cu-A laccase-mimicking enzymes can catalyze various phenols (2,4-dichlorophenol (2,4-DP), o-chlorophenol (o-CP), m-chlorophenol (m-CP), p-chlorophenol (p-CP), phenol, and catechol), the simultaneous detection of multiple phenols cannot be achieved. Based on this, a colorimetric sensor array with three buffer solutions as sensing channels was designed to identify 2, 4-dichlorophenol, o-chlorophenol, m-chlorophenol, p-chlorophenol, phenol and catechol as low as 10 μM, and even quantify 2, 4-dichlorophenol (as a model analysis). This performance was further validated by accurately identifying binary and ternary mixtures, even among 18 blind samples: containing one of the six phenols or one of the ternary mixtures. Finally, the designed sensor array was successfully applied to various simulated water samples and actual water samples to realize the identification of 6 representative phenolic substances, which provides a broad application prospect for the detection of phenolic substances in different water samples.
3. Taking Fe3+ as the central ion and aminoterephthalic acid as the ligand molecule, Fe-MIL-88B-NH2 was synthesized. As an oxidase, it uses TMB as a substrate molecule and has no catalytic activity. When incubated with 20 amino acids, only the addition of histidine showed catalytic oxidation activity to TMB. On the basis of analyzing the change of catalytic activity, the specific detection of histidine was realized.