摘要

      在废水处理过程中，应尽可能地消除抗药性基因（ARG），以防止抗药性细菌（ARB）在不同水体中的快速生长和定殖。为此，我们合成了石墨碳氮化碳、还原氧化石墨烯和氧化铁三元纳米复合材料作为可见光催化剂。这些材料通过了XPS、FTIR、PL光谱和电子显微镜的验证。光催化性能测试证实了复合材料可以被可见光激活。在可见光和过氧化氢存在下，两种含有ARGs的商用质粒DNAs  pUC 18（2686 bp）和pBR 322（4361 bp）被纳米材料成功失活并发生断裂。纳米复合材料的性能优于纯氮化碳。琼脂糖凝胶电泳证实，超螺旋质粒DNAs首先转化为单链松弛环状，然后完全断裂。质粒的光催化失活可归因于氮化碳的光催化活性、还原氧化石墨烯对光生载流子的弛豫、电子空穴对的猝灭以及过氧化氢对羟基自由基的生成，过氧化氢存在下氧化铁的光Fenton活性及氧化铁的光催化活性。

     Antibiotic resistance gene (ARG) should be eliminated during wastewater treatment to prohibit the rapid growth and colonization of antibiotic resistant bacteria (ARB) in different waterbodies. With an aim to do so, we have synthesized ternary nanocomposites of graphitic carbon nitride, reduced graphene oxide and iron oxide as visible light photocatalysts. The materials structures have been confirmed by XPS, FTIR, PL spectroscopy, and electron microscopy. The photocatalytic measurements confirmed that the composites can be activated by visible light. Two types of commercially available plasmid DNAs containing ARGs, pUC 18 (2686 bp) and pBR 322 (4361 bp) were successfully inactivated and consequently fragmented by the nanocomposite in presence of hydrogen peroxide and under visible light. The performance of nanocomposite was proven to be better than that of pure carbon nitride. Agarose gel electrophoresis confirmed that supercoiled plasmid DNAs were first converted to single stranded relaxed circular forms followed by their complete fragmentation. The photocatalytic inactivation of plasmids may be attributed to the photocatalytic activity of carbon nitride alone, relaxation of photogenerated charge carriers by reduced graphene oxide, quenching of electron-hole pairs and generation of additional hydroxyl radicals by hydrogen peroxide, photo-Fenton activity by iron oxide in presence of hydrogen peroxide and additional photocatalytic activity of iron oxide alone.

     https://www.sciencedirect.com/science/article/pii/S1385894719322673