低共熔离子液体中电沉积无机纳米材料模拟酶及其电化学传感平台的开发

The goal of this proposal is to electrodeposit non-noble metal (oxides) nanomaterials functionalized electrodes with high electrochemical activity in deep eutectic solvents, and develop their electroanalytical applications as enzyme mimics functionalized electrodes..The main contents of the project include:.1) Prepare the suitable deep eutectic solvents, electrodeposit the nanomaterials and fabricate enzyme mimics functionalized electrodes by use of one or several non-noble metal precursor(s) dissolved in deep eutectic solvents. .2) Characterize the electrochemical performances of enzyme mimics functionalized electrodes. Summarize the correlations between their electrochemical properties and properties of the deep eutectic solvent as well as the electrodeposition conditions. Optimize the electrochemical sensing ability of the modified electrodes..3) Apply the enzyme mimics to electrochemical sensing by taking their activities of peroxidase mimics as the representative parameters. With the enzyme mimics acquired, design rational multi-enzyme systems for sensing critical species in biological and environmental analysis. .(4) Real sample analysis of the above enzyme mimics and multi-enzyme modified electrodes with the pursuit of high sensitivity, fast response, and high selectivity..The significance this proposal is to fabricate sensitive and reliable enzyme mimics functionalized electrodes in cost-efficient deep eutectic solvents, and study their analytical applications by electrochemical sensing protocols. As a result, this subject is important to promote a convenient synthetic method of enzyme mimics, develop comprehensive electrochemical sensing platforms and propose a novel strategy to chemically modified electrodes.

本课题旨在利用低共熔离子液体作为电沉积模拟酶的溶剂体系，制备具有高电化学催化活性，以非贵金属/氧化物纳米材料为主的模拟酶电极，并开发其在电化学传感领域的应用。项目的主要研究内容为：(1)考察和筛选适用的低共熔离子液体体系，电沉积以非贵金属为主的纳米材料并制成模拟酶电极；(2)考察模拟酶电极的电化学性质，总结这些性质与离子液体和电沉积各参数的关联，优化模拟酶电极性能；(3)将模拟酶电极应用于电化学传感器，重点考察模拟酶作为过氧化物酶的催化活性指标。设计基于模拟酶的复合酶电极用于检测生命和环境分析中的重要指标物。(4)将模拟酶电极和复合酶电极用于实际样品分析，制成灵敏度高，响应迅速和抗干扰的功能化传感电极。本课题意义在于使用价廉易得的低共熔离子液体制备灵敏可靠的模拟酶电极并用于电化学传感器，有助于开发模拟酶制备的便捷方法，为进一步发展普适的电化学传感平台，开辟电极界面上化学修饰的新途径。

两种或多种物质以一定比例相混合，由于氢键等分子相互作用，使得混合物的熔点降低且低于100°C，所得到的混合物被称为deep eutectic solvent(DES)，中文称之为低共熔溶剂。低共熔溶剂具有与离子液体相类似的特性，有时称之为“低共熔离子液体”，“离子液体类似物”。 近年来，低共熔溶剂的相关研究往往以电沉积、 萃取分离、有机催化和气体吸收为主，拓展对此新型绿色溶剂的研究也是十分重要的。低共熔溶剂体系应当着力发展成为水相体系的重要补充，成为离子液体和有机溶剂的重要替代。纳米酶是一类具有酶活性的纳米材料。目前报道的纳米酶以氧化还原类型居多，而且往往使用TMB和ABTS作为底物用于酶活性的判断和表征。然而，广泛报道的纳米酶（以氧化物，金属和碳材料为主）难以从分子结构和催化路径上对天然酶进行模拟，也就难以实现天然酶的高活性、选择性和特异性，进而降低了模拟酶的分析化学应用价值。.本项目中，我们进行了基于低共熔溶剂体系的电化学相关应用的探索，包括电化学法制备多孔金电极用于电化学传感、组装电致变色器件和溶解金属前驱体煅烧生成纳米氧化物用于电催化析氧。然而，研究过程中发现，通过电沉积法难以实现新型、特异性的纳米酶制备。为此，我们发展了基于金属有机框架（MOF）纳米材料的纳米酶：通过模拟天然酶作用方式来获取酶的活性。我们分别采用模拟天然酶活性位点和模拟带有辅酶的天然酶的策略，制成了基于MOF-818的多酚氧化酶和PEI/ZIF/FMN氧化还原酶。此项目一方面从电解质和溶剂两层面拓展了低共熔溶剂应用价值和潜力，另一方面为基于MOF结构的仿生纳米酶贡献了新的思路。