Collaborative Research: Leveraging the interactions between carbon nanomaterials and DNA molecules for mitigating antibiotic resistance

抗抗生素细菌（“超级细菌”）被认为是21世纪人类面临的最大挑战之一。在美国，每年有超过23,000人死于抗生素耐药性细菌，每年大约花费550亿美元用于对抗抗生素耐药性。抗生素耐药细菌的传播正在引起全球的担忧，我们可能正在回到前抗生素时代。对抗生素的耐药性是由被称为抗生素抗性基因的细菌的遗传物质携带的。这些新出现的污染物正在污水处理厂等建筑环境中迅速传播。最近的研究正在探索使用碳纳米材料等新方法和新材料去除抗生素抗性基因的可行性。尽管具有巨大的潜力，但由于缺乏对抗生素抗性基因与碳纳米材料之间相互作用的深入了解，先前的研究一直报告去除效率低下。该项目的目标是了解抗生素抗性基因与碳纳米材料相互作用时的基本化学反应。基于从该项目中获得的知识，可以开发出强大的碳纳米材料膜系统，并应用于废水处理厂，以对抗抗生素耐药性。该系统还有望广泛适用于处理各种新出现的污染物，这些污染物很难用常规技术去除。除了推进工程应用和基础化学之外，该项目还将为积极性高的低收入高中学生提供教育机会。来自传统上在STEM中代表性不足的群体的本科生也将参与这项研究。这种对研究的早期接触有望在拓宽参与学生的视野和学术/职业目标方面具有变革性。抗生素耐药基因被认为是一种新兴的污染物，可以在城市污水处理厂等建筑环境中迅速传播。利用碳纳米材料吸附和降解抗生素耐药基因是对抗抗生素耐药性的一种有前途的方法。然而，由于其纳米级性质对吸附和降解的影响尚不清楚，因此文献中一直报道低效去除。该项目的目标是开发抗生素耐药基因与碳纳米材料之间相互作用的机制理解。这一目标将通过追求三个相互关联的目标来实现：1)了解与还原氧化石墨烯涂层的膜的相互作用；2)增强改性膜对耐药基因的静电吸附；3)通过改性膜增强对抗生素耐药基因的电化学降解。通过将碳纳米材料固定在膜上，这种相互作用有望在压力驱动过滤下易于调整和增强。此外，该膜可以作为碳纳米材料带电的支撑层，在阳极电位下允许静电吸附，在阴极电位下允许活性氧诱导的降解。电势的交替也会导致协同作用。该项目有望为水和废水应用的纳米结构材料和非均质纳米系统的设计提供见解。本项目制定的“捕获和清除”策略（即先吸附后降解）预计将适用于处理异质环境中新出现的污染物。该项目的一个主要好处将是解决社会需求，减轻日益增长的水和废水处理的能源需求。该项目将通过支持高中生、本科生和研究生的研究来促进教学、培训和学习。主要研究人员一直并将继续与女性工程师协会、全国黑人工程师协会和西班牙裔专业工程师协会密切合作，让传统上在STEM领域代表性不足的群体的学生参与研究。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Antibiotic resistant bacteria ("superbugs") are considered one of the greatest challenges facing humanity in the 21st century. In the U.S., more than 23,000 deaths per year are associated with antibiotic resistant bacteria, and approximately $55 billion is spent annually to combat antibiotic resistance. The spread of antibiotic resistant bacteria is causing global concern that we may be returning to a pre-antibiotic era. Resistance to antibiotics is carried by the genetic materials of bacteria called antibiotic resistance genes. These emerging contaminants are being rapidly transmitted in built environments such as wastewater treatment plants. Recent studies are exploring the feasibility of using new approaches and materials, such as carbon nanomaterials, to remove antibiotic resistance genes. Despite the great potential, previous studies consistently report inefficient removal due to a lack of in-depth understanding of the interactions between antibiotic resistance genes and carbon nanomaterials. The goal of this project is to understand the fundamental chemistry when antibiotic resistance genes interact with carbon nanomaterials. Based on the knowledge gained from this project, a robust carbon nanomaterial-membrane system can be developed and applied to wastewater treatment plants to combat antibiotic resistance. The system is also expected to be broadly applicable to the treatment of various emerging contaminants that are difficult to remove using conventional technologies. In addition to advancing engineering applications and fundamental chemistry, this project will provide educational opportunities for highly motivated, low-income high school students. Undergraduate students from groups traditionally under-represented in STEM will also be involved in the research. This early exposure to research is expected to be transformative in broadening the horizons and academic/career goals of participating students.Antibiotic resistance genes are considered an emerging contaminant and can spread rapidly in the built environment such as municipal wastewater treatment plants. One of the promising approaches to combat antibiotic resistance is the use of carbon nanomaterials to adsorb and degrade antibiotic resistance genes. However, because the effects of their nanoscale properties on adsorption and degradation are not well understood, inefficient removal is consistently reported in the literature. The goal of this project is to develop a mechanistic understanding of the interactions between antibiotic resistance genes and carbon nanomaterials. This goal will be achieved by pursuing three interrelated objectives: 1) understand the interactions with membranes coated with reduced graphene oxide; 2) enhance the electrostatic adsorption of antibiotic resistance genes on the modified membranes; and 3) enhance the electrochemical degradation of antibiotic resistance genes by the modified membranes. By immobilizing carbon nanomaterials on membranes, the interactions are expected to be readily tuned and enhanced with pressure-driven filtration. In addition, the membranes can act as a support layer for carbon nanomaterials to be electrically charged, allowing electrostatic adsorption at anodic potentials as well as reactive oxygen species-induced degradation at cathodic potentials. Alternation of the electrical potential will also result in synergistic interactions. This project is expected to provide insight into the design of nanostructured materials and heterogeneous nanosystems for water and wastewater applications. The "trap-and-zap" strategy (i.e., adsorption followed by degradation) developed in this project is expected to be applicable to the treatment of emerging contaminants in heterogeneous environments. A major benefit of this project will be addressing the societal need for alleviating the ever-growing energy demand for water and wastewater treatment. This project will promote teaching, training, and learning by supporting \high school, undergraduate, and graduate students in research. The principal investigators have been and will continue working closely with the Society of Women Engineers, the National Society of Black Engineers, and the Society of Hispanic Professional Engineers to engage students from groups traditionally under-represented in STEM in research.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.