Bharti Kanika, Sadhu Kalyan K
Department of Chemistry, Indian Institute of Technology Roorkee, Roorkee 247667, India.
Biointerphases. 2025 Jul 1;20(4). doi: 10.1116/6.0004563.
Syntheses of gold-manganese oxide nanocomposites were attempted by a redox-mediated growth method under varying mild reaction conditions with amino acid as a stabilization agent; finally, the nanocomposites were applied for superoxide dismutase (SOD)-mimic activity. Growth reaction was performed by the reduction of Au(III) with Mn(0) powder on the surface of citrate-stabilized gold nanoparticles as seeds. Variable reaction conditions were attempted to monitor the effect of the pH and, finally, optimized based on the critical properties of the nanocomposites including their long-term stability. In a neutral medium, tryptophan-stabilized Au-Mn3O4 nanocomposites were obtained. Stable Au-Mn2O3 nanocomposites were formed at basic pH in the presence of hydrophobic amino acids. The present work elucidates the role of amino acids, especially tryptophan, in stabilizing gold-manganese oxide nanocomposites. The effect of crystalline vs. the amorphous nature of Mn3O4 sheets in the tryptophan-stabilized nanocomposites was evaluated in SOD-mimetic applications. The IC50 values for the newly synthesized Au-Mn3O4 nanocomposites with crystalline or amorphous Mn3O4 sheets at room temperature were found to be 125 times and 25 times better with respect to the reported Mn3O4 nanoparticles synthesized after calcination at 600 °C. These results provide useful insights into the synthesis of gold-manganese oxide nanocomposites with tunable properties and their potential applications in the growing field of nanozymes.
尝试通过氧化还原介导的生长方法，以氨基酸作为稳定剂，在不同的温和反应条件下合成金-锰氧化物纳米复合材料；最后，将这些纳米复合材料用于超氧化物歧化酶（SOD）模拟活性研究。生长反应是通过在柠檬酸盐稳定的金纳米颗粒表面上用Mn(0)粉末还原Au(III)来进行的，这些金纳米颗粒作为种子。尝试了不同的反应条件以监测pH值的影响，最后根据纳米复合材料的关键特性（包括其长期稳定性）进行优化。在中性介质中，获得了色氨酸稳定的Au-Mn3O4纳米复合材料。在碱性pH值下，在疏水性氨基酸存在的情况下形成了稳定的Au-Mn2O3纳米复合材料。本工作阐明了氨基酸，特别是色氨酸，在稳定金-锰氧化物纳米复合材料中的作用。在SOD模拟应用中评估了色氨酸稳定的纳米复合材料中Mn3O4片层的晶体与非晶性质的影响。发现新合成的具有晶体或非晶体Mn3O4片层的Au-Mn3O4纳米复合材料在室温下的IC50值分别比在600°C煅烧后合成的报道的Mn3O4纳米颗粒好125倍和25倍。这些结果为合成具有可调谐性质的金-锰氧化物纳米复合材料及其在不断发展的纳米酶领域的潜在应用提供了有用的见解。
