MXenes基量子点纳米酶的电化学可控制备及传感应用中催化活性优化策略研究

Enzyme sensors are of great significance for the rapid and sensitive detection in the fields of disease diagnosis, food safety, environmental health, etc. However, the natural enzymes are with shortcoming of less content, time-consuming preparation, high cost and poor stability. While the catalytic efficiency of the reported mimic nanozyme is still relatively low. Therefore, it is in urgent need to develop new nanomaterials as nanozymes that are with superiorities of rich source, low cost, high catalytic performance and good stability. The quantum dots derived from two-dimensional materials (2D-QDs) possess excellent catalytic activity due to the quantum confinement and edge effects, but the related research is still rare. Herein, the project is to develop new 2D-QDs with nanozyme properties applying the two-dimensional material MXenes as precursors. MXenes are a relatively young class of two-dimensional materials, which are composed of layered transition metal carbides, nitrides or carbon nitrides. They are rich in element compositions and the components can be adjusted with flexibly. In addition, the simple, fast, low-consumption electrochemical method will be used to achieve the controllable preparation. Meanwhile, the relationship between the components, size, surface groups and the catalytic activity will be investigated. Subsequently the catalysis mechanism will be analyzed. For example, chemical titration method can be applied to selectively deactivate the oxygen-containing functional groups on the surfaces of the 2D-QDs to identify the active or inhibitory sites of the prepared nanozyme. Furthermore, appropriate design of suitable matrix materials and binding methods will be applied to reduce the inhibitory sites of the nanozyme. Accordingly, the active sites can be increased to enhance the corresponding catalytic activity. As a result, the optimized enzymes will be used to develop sensors for detecting the disease markers such as glucose and cholesterol in practical samples such as blood or urine via either a single-enzyme or a multi-enzyme system.

酶传感器在疾病诊断、食品安全、环境卫生等领域的快速灵敏检测方面意义重大，但天然酶含量少、制备耗时、成本高、稳定性差；而已报道的纳米模拟酶催化效率仍相对较低。因此研制来源丰富、价格低廉、催化性能和稳定性高的新型纳米酶材料迫在眉睫。二维材料量子点（2D-QDs）由于限域和边缘效应具有极佳的催化活性，但目前相关研究尚浅。鉴于此，本项目拟以组成元素丰富、组分灵活可调的MXenes（过渡金属碳、氮或碳氮化物）二维材料作为前驱体，采用简单、快速、低耗的电化学方法实现2D-QDs纳米酶的可控制备。同时考察其组分、尺寸、表面基团等与催化活性之间的关系，探明其催化机制，如采用化学掩蔽法确定作为酶活性位点或抑制位点的2D-QDs表面基团等。进一步设计合适的基体材料和键合方法以消耗纳米酶的抑制位点、增加活性位点以提高其催化活性，进而构建单酶或多酶传感体系，并用于实际样品中葡萄糖、胆固醇等疾病标志物的高效检测。

本项目以组成元素丰富、组分灵活可调的MXenes（过渡金属碳、氮或碳氮化物）二维材料作为前驱体，采用简单、快速、低耗的电化学方法，同时拓展使用水热法等制备方法，实现二维材料衍生量子点（2D-QDs）纳米酶的可控制备。同时考察了其组分、尺寸、表面基团等与催化活性之间的关系，探明其催化机制，如采用化学掩蔽法确定作为酶活性位点或抑制位点的2D-QDs表面基团等。进一步通过设计磁性载体等基体材料和键合方法以消耗纳米酶的抑制位点、增加活性位点以提高其催化活性，进而构建单酶或多酶传感体系，并用于实际样品中葡萄糖、胆固醇、过氧化氢、DNA等疾病标志物的高效检测。本项目严格按照计划书要求，在2019年1月至2022年12月项目执行期间，已顺利执行所有研究计划，超额完成了研究目标，发表SCI论文26篇，申请专利12项，授权3项，获得教育部“长江学者奖励计划”青年学者、山东省杰出青年基金、山东省泰山学者青年专家、青岛拔尖人才、青岛市科学技术奖自然科学三等奖等项目和奖项。本项目所建立的基于新型高效纳米酶的传感器在疾病诊断、食品安全、环境卫生等领域的快速灵敏检测方面具有重要意义。自2019年01月以来，培养博士后出站人数2人，博、硕士毕业生21人，目前在读硕士研究生15人、博士研究生2人，项目负责人从2019-2022连续4年被评委青岛大学优秀研究生指导教师，并获得2019年山东省优秀研究生指导教师。在项目执行期间，积极开展团队建设、产学研等工作，团队获批山东高等学校青年创新团队发展计划立项，项目负责人作为常务副主任获批青岛市生物分析与健康应用工程研究中心，作为建设单位负责人共同建设山东省工业技术研究院干细胞药物研究协同创新中心，作为负责人获批山东省高等学校黄河流域盐碱地综合治理和高质量发展协同创新中心。