棒状β-FeOOH纳米酶的制备及其类酶催化机理研究

A novel rod-likedβ-FeOOH nanozyme synthesis and the study of peroxidase mimetic activity

纳米酶是一种可模拟天然酶催化活性的纳米材料,具有催化活性高、制备简单、易于储存等优点,已被广泛用于实际生产当中.本文采用了简单的低温水解沉淀法,以聚乙烯亚胺为生长模板,在水相中制备了一种具有类过氧化物酶活性的β-FeOOH纳米棒.利用透射电子显微镜(TEM)、扫描电子显微镜(SEM)、傅立叶红外光谱(FTIR)、粉末X-射线衍射(XRD)、X光电子能谱(XPS)等测试对β-FeOOH纳米棒进行了形貌成份的表征.结果表明,β-FeOOH纳米棒具有良好的稳定性和分散性;与天然过氧化物酶(HRP)相比,β-FeOOH纳米棒对底物的亲和力相似,反应速率是HRP的2.6倍,可催化四甲基联苯胺(TMB)生成蓝绿色氧化产物.此外,采用分光光度法,以水杨酸为捕获剂,验证了β-FeOOH纳米棒可催化双氧水分解,产生羟基自由基,实现TMB的氧化,达到类酶催化效果.本研究为纳米酶取代天然酶提供了一种新材料.

Nanozyme,a kind of nanomaterials,which can simulate the catalytic activity of natural enzymes,has attracted tremendous attention in catalysis due to their high catalytic activity,easy synthesis,and simple storage.This work reports the synthesis of water-dispersible and biocompatibleβ-FeOOH nanorod via a simple hydrolytic precipitation method,exploring polyethyleneimine(PEI)as a model.The synthesized nanorod possesses excellent water-dispersion and stability,measured by TEM,SEM,FTIR,XRD,and XPS.Using TMB and H2O2 as substrates,β-FeOOH nanorod exhibits similar affinity for substrates,while the reaction rate is 2.6 times of natural HRP enzyme,indicating a higher peroxidase mimetic activity to catalyze the formation of tetramethylbenzidine(TMB)into blue-green oxidation products.Exploring salicylic acid as the trapping agent andβ-FeOOH nanorod as an enzyme,the hydroxyl radical generated by the decomposition of H2O2 could be detected,showing the excellent mimetic activity as a potential replacement of natural enzyme.