超分子手性聚苯胺-金复合纳米酶的构建及其对映选择性催化  

Construction of Supramolecular Chiral Polyaniline-Gold Nanocomposite as Nanozyme for Enantioselective Catalysis

作　　者：袁干印 奚政 王楚 孙晓环 韩杰[1] 郭荣[1] Ganyin Yuan;Zheng Xi;Chu Wang;Xiaohuan Sun;Jie Han;Rong Guo(School of Chemistry and Chemical Engineering,Yangzhou University,Yangzhou 225002,Jiangsu Province,China)

机构地区：[1]扬州大学化学化工学院,江苏扬州225002

出　　处：《物理化学学报》2023年第7期1-7,共7页Acta Physico-Chimica Sinica

基　　金：国家自然科学基金(21922202,22002138,22202171)资助项目。

摘　　要：对映选择性催化是生物体内普遍存在的反应,与生命的产生代谢有着非常紧密的联系。设计研发具有高对映选择性催化效果的纳米酶在各类生物医药相关领域都至关重要。目前,关于纳米酶的研究大都集中在提高其催化活性,而涉及纳米酶对映选择性的研究相对较少。已有对映选择性酶催化报道表明,手性纳米酶主要通过手性分子修饰纳米颗粒来构建。考虑到天然酶的选择性不仅仅取决于氨基酸等手性分子的手性,而且与蛋白质空间排列和折叠所产生的超分子手性微环境密切相关,因此构建具有超分子手性微环境的纳米酶也成为设计具有优异对映选择性纳米酶的有效途径。此外,为了进一步提高手性纳米酶的对映选择性,深入理解手性纳米酶选择性因子的影响因素也成为一个重要研究方向。基于此,本文构建了一种由不含任何手性分子的M-聚苯胺(M-PANI)扭曲纳米带和三种不同尺寸(3、10和16nm)的金纳米颗粒(AuNPs)组成的超分子纳米复合材料。扫描电子显微镜、透射电子显微镜、紫外-可见吸收光谱和X射线光电子能谱结果证实了M-PANI-Au超分子纳米复合材料的成功制备。同时,圆二色光谱显示M-PANI-Au超分子复合材料具有清晰的手性信号,表明它们在手性纳米催化方面具有潜在应用。以手性R-/S-3,4-二羟基苯丙氨酸(R-/S-DOPA)对映体的催化氧化为模型反应,该类纳米酶对R-DOPA的催化选择性均高于对S-DOPA。进一步研究表明,得益于超分子手性聚苯胺载体和3 nm AuNPs之间的强手性传递作用,3 nm AuNPs(2.59)负载的M-PANI比10 nm AuNPs(1.46)和16 nm NPs(1.58)负载的M-PANI具有更高的选择因子。这一发现阐明了手性转移是调控对映选择性催化的关键影响因素,为负载型超分子手性纳米酶的构建和设计提供了方向和指导。Enantioselective catalysis is ubiquitous in biological organisms and closely related to biological production and metabolism.The design and development of nanozymes with high enantioselectivities are essential for various bio-related applications.Currently,investigations of nanozymes are primarily focused on their catalytic activity.However,the enantioselectivity of nanozymes,a significant feature,has been rarely studied.In view of the few reports related to enantioselective catalysis,nanozymes have mainly been constructed with chiral molecule-modified nanoparticles.Because the selectivity of natural enzymes not only depends on the molecular chirality of chiral species,such as amino acids,but is also closely related to the chiral supramolecular microenvironment generated by the spatial arrangement and folding of proteins,the construction of active chiral substances with chiral supramolecular microenvironment for nanozymes is also an effective way to design nanozymes with excellent enantioselectivities.Additionally,to improve the enantioselectivity,an understanding of the influencing parameters for select factor of chiral nanozymes is essential.Herein,we report the successful construction of nanocomposites composed of supramolecular M-polyaniline(M-PANI)twisted nanoribbons assembled without any chiral molecules,and Au nanoparticles(NPs)of three different sizes(3,10,and 16 nm).The characterization results from scanning electron microscopy,transmission electron microscopy,UV-Vis absorption spectroscopy,and X-ray photoelectron spectroscopy confirmed the successful fabrication of M-PANI-Au nanocomposites.The evident signals in the circular dichroism spectra of the M-PANI-Au nanocomposites indicated their potential as chiral nanozymes.Considering the catalytic oxidation of chiral R-/S-3,4-dihydroxyphenylalanine(R-/S-DOPA)enantiomers as a model reaction,the three M-PANI supported Au NPs demonstrated higher catalytic selectivity for R-DOPA than for S-DOPA,as confirmed by the kinetic absorption curves,revealing the high p

关 键 词：超分子手性 对映选择性催化 手性聚苯胺 金纳米颗粒 纳米酶 

分 类 号：O643[理学—物理化学] O648[理学—化学]