Abstract：
Photo-oxidase nanozymes are emerging enzyme-mimicking materials that produce reactive oxygen species (ROS) upon light illumination and subsequently catalyze the oxidation of the substrate. Carbon dots are promising photo-oxidase nanozymes due to their biocompatibility and straightforward synthesis. Carbon dot-based photo-oxidase nanozymes become active for ROS generation under UV or blue light illumination. In this work, sulfur and nitrogen doped carbon dots (S,N-CDs) were synthesized by solvent-free, microwave assisted technique. We demonstrated that sulfur, nitrogen doping of carbon dots (band gap of 2.11 eV) has enabled photo-oxidation of 3,3,5,5\'-tetramethylbenzidine (TMB) with extended visible light (up to 525 nm) excitation at pH 4. The photo-oxidase activities by S,N-CDs produce Michaelis-Menten constant (Km ) of 1.18 mM and the maximum initial velocity (Vmax ) as 4.66×10-8 Ms-1 , under 525 nm illumination. Furthermore, visible light illumination can also induce bactericidal activities with growth inhibition of Escherichia coli (E. coli). These results demonstrate that S,N-CDs can increase intracellular ROS in the presence of LED light illumination.
摘要：
光氧化酶纳米酶是新兴的酶模拟材料，在光照下产生活性氧（ROS）并随后催化底物的氧化。碳点由于其生物相容性和简单的合成而成为有前途的光氧化酶纳米酶。基于碳点的光氧化酶纳米酶在UV或蓝光照射下变得对ROS产生有活性。在这项工作中,硫和氮掺杂的碳点（S，N-CD)是通过无溶剂合成的，微波辅助技术。我们已经证明了硫，碳点的氮掺杂（带隙为2.11eV）使3,3,5,5'-四甲基联苯胺（TMB）在pH=4的扩展可见光（高达525nm）激发下光氧化。S的光氧化酶活性，在525nm照射下,N-CD产生1.18mM的米氏-Menten常数(Km)和4.66×10-8Ms-1的最大初始速度(Vmax)。此外，可见光照射也可以诱导杀菌活性，抑制大肠杆菌的生长（E。大肠杆菌）。这些结果表明，S，在存在LED光照明的情况下,N-CD可以增加细胞内ROS。
