(3fx) Electronic Biosensors for Implantable and Wearable Applications

Research Interests

The design of high performance electronic and miniaturized biosensors is critical for next-generation implantable and wearable devices towards uncovering the mechanisms of physiological processes and facilitating disease diagnosis and prevention. With sophisticated training from medicinal chemistry and chemical biology, I am very interested in developing molecular diagnostic methodologies to enable physiological information acquisition. I have utilized the advanced sensing interfaces for brain recording as well as wireless non-invasive biofluid analysis.

As a graduate student in Prof. Monbouquette’s lab in the Department of Chemical Engineering, I focused on the development of electrochemical sensing platforms and the creation of implantable microprobes for continuous biomarker analysis. I created multiple high-performance electroenzymatic sensors, including glutamate, choline, glucose, and hydrogen peroxide, based on designing and implementing permselective membrane-enabled methodologies to exclude common interfering species. The sensing technologies were successfully transferred to silicon-based microprobes. To enable multi-analyte sensing capability, I devised a generalizable microstamping strategy to transfer a variety of biomolecules onto closely juxtaposed microelectrodes.

To apply my developed implantable biosensing probes for brain recording, I joined the research group of Prof. Maidment as a postdoctoral scholar in the Semel Institute for Neuroscience & Human Behavior. In collaboration with scientists from different departments, I developed a complete and multifunctional PDMS/Si hybrid neural probe for multi-analyte recording and in situ chemical delivery in the rodent brain, with the dual benefits of reducing brain damage and surgical complexity. In addition, we demonstrated a soft and fully stretchable PDMS probe with tunable stiffness for both in vivo neurochemical recording and chemical modulation with improved biocompatibility.

To apply my skills in biosensor development and microdevice fabrication to the projects of developing wearable and mobile health devices for personalized monitoring, I continued my postdoc training in the research group of Prof. Emaminejad in the Electrical Engineering department. I have realized multiple electronic biosensing systems based on both conventional electrochemical methods and transistors for wireless and non-invasive biomarker analysis (e.g., metabolites, hormones, nutrients, and drugs in sweat and saliva). The devised biosensing interfaces were embedded within sophisticated epidermal microfluidic structures and interfaced with flexible printed circuit boards to achieve system-level functionality. These sensing systems have been successfully deployed for wireless sweat and saliva analysis in various human subject studies. These newly developed techniques open up many excellent opportunities for personalized health monitoring.

My future research seeks to develop fundamental understandings of the working principles and strategies in creating novel electronic biosensing interfaces for complex biofluid analysis. By leveraging the developed biosensing platforms, I will develop (1) implantable neural probes to facilitate the understanding of neuronal process underlying complex behaviors and (2) design wearable and wireless biosensing systems to address the intermeshed engineering bottlenecks and scientific questions regarding non-invasive personalized health monitoring. Working on various research topics and interacting with scientists and engineers from different technical backgrounds have made me appreciate the advantages and power of an interdisciplinary research program, inspiring me to pursue a wide variety of research projects and collaborations in my own group.

Selected Publications (^§ equal contribution)

1. B. Wang^§, X. Wen^§, Y. Cao, S. Huang, H. Lam, T. Liu, P.-S. Chung, H. G. Monbouquette, P.-Y. Chiou, N. T. Maidment, “A Multifunctional Neural Microprobe for Simultaneous Multi-Analyte Sensing and Chemical Delivery”, Lab Chip, 2020, 20, 1390–1397.
2. Y. Zhao^§, B. Wang^§, H. Hojaiji, Z. Wang, S. Lin, C. Yeung, H. Lin, P. Nguyen, K. Chiu, K. Salahi, X. Cheng, J. Tan, B. A. Cerrillos, S. Emaminejad, “A Wearable Freestanding Electrochemical Sensing System”, Sci. Adv., 2020, 6, eaaz0007.
3. S. Lin^§, B. Wang^§, W. Yu, K. Castillo, C. Hoffman, Y. Gao, Z. Wang, Y. Zhao, X. Cheng, H. Lin, H. Hojaiji, J. Tan, S. Emaminejad, “A Design Framework and Sensing System for Non-invasive Wearable Electroactive Drug Monitoring”, ACS Sens., 2020, 5, 265−273.
4. S. Lin^§, B. Wang^§, , Y. Zhao, R. Shih, X. Cheng, W. Yu, H Hojaiji, H. Lin, C. Hoffman, D. Ly, J. Tan, Y. Chen, D. Di Carlo, C. Milla, S. Emaminejad, “Natural Perspiration Sampling and In-Situ Electrochemical Analysis with Hydrogel Micropatches for User-Identifiable and Wireless Chemo/bio-sensing”, ACS Sens., 2020, 5, 93−102.
5. B. Wang, X. Wen, P.-Y. Chiou, N. T. Maidment, “Pt Nanoparticle-Modified Carbon Fiber Microelectrode for Selective Electrochemical Sensing of Hydrogen Peroxide”, Electroanal., 2019, 31, 1641–1645.
6. X. Cheng^§, B. Wang^§, Y. Zhao^§, H. Hojaiji, S. Lin, R. Shih, H. Lin, S. Tamayosa, B. Ham, P. Stout, K. Salahi, Z. Wang, C. Zhao, J. Tan, S. Emaminejad, “A Mediator-free Electroenzymatic Sensing Methodology to Mitigate Ionic and Electroactive Interferents’ Effects for Reliable Wearable Metabolite and Nutrient Monitoring”, Adv. Funct. Mater., 2019, 10, 1908507.
7. B. Wang^§, L. Feng^§, B. Koo, H. G. Monbouquette, “A Complete Electroenzymatic Choline Microprobe Based on Nanostructured Platinum Microelectrodes and an IrOx On-probe Reference Electrode”, Electroanal., 2019, 31, 1249-1253.
8. X. Wen^§, B. Wang^§, S. Huang, M.-S. Lee, P.-S. Chung, Y. T. Chow, I-W. Huang, H. G. Monbouquette, N. T. Maidment, P.-Y. Chiou, “Flexible, Multifunctional Neural Probe with Liquid Metal Enabled, Ultra-Large Tunable Stiffness for Deep-Brain Chemical Sensing and Agent Delivery”, Biosens. Bioelectron., 2019, 131, 37-45.
9. B. Wang^§, B. Koo^§, L. Huang, H. G. Monbouquette, “Microbiosensor Fabrication by Polydimethylsiloxane Stamping for Combined Sensing of Glucose and Choline”, Analyst, 2018, 143, 5008-5013.
10. B. Wang, B. Koo, H. G. Monbouquette, “Enzyme Deposition by Polydimethylsiloxane Stamping for Biosensor Fabrication”, Electroanal., 2017, 29, 2300-2306.

Teaching Interests

My experiences in fundamental science, engineering, and translational medicine have made me passionate about teaching. I am excited to provide education and training for future generations of interdisciplinary scientists and engineers in the STEM fields. At the University of California, Los Angeles, I have been a teaching assistant for multiple chemical engineering classes and lab sessions for undergraduate and graduate students, including Fundamentals of Chem & Biochem Engineering course (~100 students). I have mentored several undergraduates, M.S., and Ph.D. students during my graduate training and now as a postdoc. I was also invited as a guest lecturer for a graduate course in the Electrical Engineering department on “Electrochemical Biosensors” for the past two years.

These experiences and my interdisciplinary background have trained my ability to explain difficult concepts simply and logically. Given my background in both science and engineering, I can teach a variety of undergraduate and graduate courses such as Fundamentals of Chemical Engineering, Electrochemical Methods, Molecular Diagnostics, Thermodynamics, and Surface Chemistry.