College of Environmental Science and Engineering, Nanjing Tech University, Nanjing, Jiangsu 211816, China.
Department of Civil and Environmental Engineering, Rice University, Houston, Texas 77005, United States.
Environ Sci Technol. 2020 Apr 7;54(7):4621-4630. doi: 10.1021/acs.est.9b06926. Epub 2020 Mar 17.
There is a growing need to mitigate the discharge of extracellular antibiotic resistance genes (ARGs) from municipal wastewater treatment systems. Here, molecularly-imprinted graphitic carbon nitride (MIP-CN) nanosheets were synthesized for selective photocatalytic degradation of a plasmid-encoded ARG (, coding for multidrug resistance New Delhi metallo-β-lactamase-1) in secondary effluent. Molecular imprinting with guanine enhanced ARG adsorption, which improved the utilization of photogenerated oxidizing species to degrade rather than being scavenged by background nontarget constituents. Consequently, photocatalytic removal of in secondary effluent with MIP-CN ( = 0.111 ± 0.028 min) was 37 times faster than with bare graphitic carbon nitride ( = 0.003 ± 0.001 min) under UVA irradiation (365 nm, 3.64 × 10 Einstein/L·s). MIP-CN can efficiently catalyze the fragmentation of , which decreased the potential for ARG repair by transformed bacteria. Molecular imprinting also changed the primary degradation pathway; electron holes (h) were the predominant oxidizing species responsible for removal with MIP-CN versus free radicals (i.e., ·OH and O) for coated but nonimprinted CN. Overall, MIP-CN efficiently removed from secondary effluent, demonstrating the potential for molecular imprinting to enhance the selectivity and efficacy of photocatalytic processes to mitigate dissemination of antibiotic resistance from sewage treatment systems.
从城市污水处理系统中减轻细胞外抗生素耐药基因（ARGs）排放的需求日益增长。在这里，合成了分子印迹石墨相氮化碳（MIP-CN）纳米片，用于选择性光催化降解二级出水中质粒编码的 ARG（，编码多药耐药新德里金属β-内酰胺酶-1）。与鸟嘌呤的分子印迹增强了 ARG 的吸附，从而提高了光生氧化物种的利用效率，以降解 ，而不是被背景非目标成分猝灭。因此，在 UVA 照射（365nm，3.64×10 Einstein/L·s）下，MIP-CN（ = 0.111 ± 0.028 min）对二级出水中的 进行光催化去除的速度比裸露石墨相氮化碳（ = 0.003 ± 0.001 min）快 37 倍。MIP-CN 可以有效地催化 的碎片化，从而降低了转化细菌修复 ARG 的潜力。分子印迹还改变了主要的降解途径；与涂层但非印迹的 CN 相比，电子空穴（h）是 MIP-CN 去除 的主要氧化物种，而自由基（即·OH 和 O）是其主要氧化物种。总体而言，MIP-CN 有效地从二级出水中去除了 ，证明了分子印迹在增强光催化过程的选择性和效率以减轻污水处理系统中抗生素耐药性传播方面的潜力。
