(4eg) Integrated Electroactive Biofilm-Based Bioelectronics

Since the invention of integrated circuits, the demand for silicon-based semiconductors in everyday life has increased significantly. However, the fabrication of these devices is resource-intensive, requiring copious amounts of energy and water, and it produces hazardous waste. So, there is an urgent need to transition to sustainable electronics and the use of eco-friendly materials. Biomaterials offer great potential in this regard, with their novel properties, complex composition and structures, and little to zero carbon footprint. However, the construction of semiconductors requires biomaterials to be conductive. Address the conductivity issues, we find some bacteria known as electroactive bacteria, have the capability to deliver electrons as electrical signals. However, these bacteria are mainly planktonic phenotypes (i.e., free-floating, non-biofilm cells), leading to inefficient signal transduction for further applications. To overcome the challenges, my future research focuses on creating integrated electroactive biofilm (EAB)-based bioelectronics to enhance the signal delivery efficiency, which could further function in renewable bioelectricity, on-site biosensing, and bioremediations.

This proposal builds on my extensive research experience into an innovative field. My prior research experience has focused on the fundamental study and functional applications of microbial electron transfer, utilizing electrochemical methods and synthetic biology tools. Specially, I have utilized electrochemical techniques explore the mechanisms of electron transfer within biofilm matrices and to manipulate biological performance via novel electrochemical inputs^1-4. Moreover, by integrating synthetic biology tools, I have developed bioelectronic sensors that address key challenges in whole-cell biosensors. These achievements include: 1) real-time monitoring of individual toxins; 2) multiplex sensing and identifying heavy metals as 2-bit binary signals. Build on my solid foundation in electrochemical techniques and synthetic engineering, my future research plans will integrate these core strengths to pioneer novel insights and technologies in the bioelectronics field.

To develop the proposed biofilm-based bioelectronics, my research will explore the microbial electron transfer across a spectrum of scales and integrate it with diverse biological functions for practical applications (Fig 1). It encompasses three-tiered thrusts: 1) Establishing microbe-material interactions to develop conductive biofilms. 2) Investigating architecture design on cellular interactions. 3) Constructing a hybrid biofilm-based bioelectronics platform. I plan to develop a hybrid, all-in-one bioelectronic platform that could serve as portable sensors for diagnostics, and as a system for continuous, low-dose drug delivery. Moving forward, I envision these integrated bioelectronics evolving into intelligent, high-capacity systems capable of wireless communication, offering significant opportunities for environmental protection and healthcare applications.

References:

1. Zhang, X., Prévoteau, A., Louro, R. O., Paquete, C. M. & Rabaey, K. Periodic polarization of electroactive biofilms increases current density and charge carriers concentration while modifying biofilm structure. Biosensors and Bioelectronics 121, 183–191 (2018).
2. Zhang, X., Rabaey, K. & Prévoteau, A. Reversible Effects of Periodic Polarization on Anodic Electroactive Biofilms. ChemElectroChem 6, 1921–1925 (2019).
3. Zhang, X. et al. Rapid and Quantitative Assessment of Redox Conduction Across Electroactive Biofilms by using Double Potential Step Chronoamperometry. ChemElectroChem 4, 1026–1036 (2017).
4. Atkinson, J. T. et al. Real-time bioelectronic sensing of environmental contaminants. Nature 611, 548–553 (2022).

Teaching Interests

Teaching and mentoring are the central responsibilities of the role of a professor, with the unique power to guide students towards their career development opportunities. My diverse academic journey, from studying in Europe to postdoctoral work in the US, has equipped me with rich research experiences. I have gained unique insights into the dynamics of both teaching and learning and fostered a deep passion for educating and guiding the next generation. In the classroom, I aim to train students to be creative, independent thinkers, igniting their passion for science and its potential societal benefits. For research mentoring, I will help raise their passion for science by teaching them how to collaborate across disciplines to solve global challenges and push the boundaries of fundamental understanding of electrochemistry and biology and the technical capabilities of synthetic biotechnologies.

Class Teaching. I would like to help and train students to apply scientific processes to formulate knowledge and understanding. To achieve this, I plan to use inquiry-based learning (IBL) methods, which guide students to identify problems and then conduct experiments to conclude.¹ There are different stages of the inquiry cycle (e.g., formulating a question, determining designing an experiment, and drawing a conclusion) and levels of inquiry (e.g., lecturer-specified restricted inquiry or student-specified open-ended research projects).² Some classes with bigger sizes and scopes are often taught in a didactic lecture format, which is effective but might limit opportunities for students to engage in inquiry. To address this, I plan to make a few adjustments: (i) Having a pre-assessment of the current level of IBL activities. (ii) Adding think-pair-share activities in class sessions to encourage students to work together, answer a question, and interpret a piece of data from the literature to draw conclusions.³ (iii) Introducing some activities to help organize and synthesize connections of their knowledge, such as concept mapping exercises⁴. (iv) Focusing on problem sets and exams toward the application of knowledge and away from rote memorization.

Research Mentoring. My goal is to help the next generation of scientists passionate about their science to identify their career paths and develop transferable skills. Through weekly meetings, I will inspire and support their work, give them full credit for their efforts, and give them access to all development opportunities. During annual reviews, I will encourage them to think proactively about their career paths, help them to identify yearly goals, and plan steps to achieve them. To develop their transferable skills, I will hone their communication skills through regular presentations, refine their writing skills by drafting manuscripts and fellowships applications, and cultivate their mentorship skills by mentoring junior students.

I am also interested in teaching elective classes that explore the transformative synergy between electrochemistry, synthetic biology, and other disciplines, such as Special Topics in Bioelectronics, and Biotechnology. I will welcome students from different academic backgrounds into my classroom in order to highlight that the contributions to this field, as well as its possibilities, are multifaceted. My goal is to teach students the value of an interdisciplinary engineering approach that they can adopt in their future research and careers.

Reference:

1. M. Mäeots, M. Pedaste, & T. Sarapuu. Transforming Students’ Inquiry Skills with Computer-Based Simulations. in 2008 Eighth IEEE International Conference on Advanced Learning Technologies 938–942 (2008). doi:10.1109/ICALT.2008.239.
2. Willison, J. & O’Regan, K. Commonly known, commonly not known, totally unknown: a framework for students becoming researchers. Higher Education Research & Development 26, 393–409 (2007).
3. Tanner, K. D. Talking to Learn: Why Biology Students Should Be Talking in Classrooms and How to Make It Happen. LSE 8, 89–94 (2009).
4. Allen, D. & Tanner, K. Approaches to Cell Biology Teaching: Mapping the Journey—Concept Maps as Signposts of Developing Knowledge Structures. CBE 2, 133–136 (2003).