Tripathi Kumud Malika, Ahn Hee Tae, Chung Minsoo, Le Xuan Ai, Saini Deepika, Bhati Anshu, Sonkar Sumit Kumar, Kim Moon Il, Kim TaeYoung
Department of Chemistry, Indian Institute of Petroleum and Energy, Visakhapatnam 530003, Andhra Pradesh, India.
Department of BioNano Technology, Gachon University, 1342 Seongnam-daero, Sujeong-gu, Seongnam, Gyeonggi 13120, South Korea.
ACS Biomater Sci Eng. 2020 Oct 12;6(10):5527-5537. doi: 10.1021/acsbiomaterials.0c00831. Epub 2020 Sep 16.
Nanozymes have drawn significant scientific interest due to their high practical importance in terms of overcoming the instability, complicated synthesis, and high cost of protein enzymes. However, their activity is generally limited to particular pHs, especially acidic ones. Herein, we report that luminescent N, S, and P-co-doped carbon quantum dots (NSP-CQDs) act as attractive peroxidase mimetics in a wide pH range, even at neutral pH, for the peroxidase substrate 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) in the presence of HO. The synergistic effects of multiple heteroatoms doping in CQDs boost the catalytic activity in a wide pH range attributed to the presence of high density of active sites for enzymatic-like catalysis and accelerated electron transfer during the peroxidase-like reactions. A possible reaction mechanism for the peroxidase-like activity of CQDs is investigated based on the radical trapping experiments. Moreover, the multifunctional activity of NSP-CQDs was further utilized for antibacterial assays for both Gram-negative and Gram-positive model species, including () and (), respectively. The growths of the employed and were found to be significantly inhibited due to the peroxidase-mediated perturbation of cell walls. The present work signifies the current advance in the rational design of N, S, and P-co-doped CQDs as highly active peroxidase mimics for novel applications in diverse fields, including catalysis, medical diagnostics, environmental chemistry, and biotechnology.
由于纳米酶在克服蛋白质酶的不稳定性、复杂合成和高成本方面具有高度的实际重要性，因此引起了科学界的极大兴趣。然而，它们的活性通常仅限于特定的pH值，尤其是酸性pH值。在此，我们报告发光的氮、硫和磷共掺杂碳量子点（NSP-CQDs）在宽pH范围内，甚至在中性pH条件下，对于过氧化物酶底物2,2'-联氮-双（3-乙基苯并噻唑啉-6-磺酸）（ABTS）在过氧化氢存在的情况下，可作为有吸引力的过氧化物酶模拟物。碳量子点中多杂原子掺杂的协同效应在宽pH范围内提高了催化活性，这归因于存在高密度的类酶催化活性位点以及过氧化物酶样反应过程中加速的电子转移。基于自由基捕获实验研究了碳量子点过氧化物酶样活性的可能反应机制。此外，NSP-CQDs的多功能活性进一步用于革兰氏阴性和革兰氏阳性模式菌种的抗菌测定，分别包括（）和（）。由于过氧化物酶介导的细胞壁扰动，发现所使用的（）和（）的生长受到显著抑制。目前的工作标志着在合理设计氮、硫和磷共掺杂碳量子点作为高活性过氧化物酶模拟物以用于包括催化、医学诊断、环境化学和生物技术在内的不同领域的新应用方面的当前进展。
