In a groundbreaking development, researchers have designed a highly sensitive and selective sensor for detecting copper (Cu(II)) ions using carbon fiber microelectrodes. This innovative approach, detailed in a recent publication in the journal RSC Advances, represents a significant leap forward in the field of electrochemical sensing.
The research team, led by Dr. Yangguang Ou including Uma Nudurupati, Terdha Narla, and Dr. David Punihaole from the University of Vermont, developed a platform based on the anodic deposition of ethynyl linkers, specifically 1,4-diethynylbenzene (DEB), onto carbon fiber microelectrodes. Dr. Ou emphasized the novelty and potential impact of their work: “This study is the first to demonstrate the successful anodic deposition of ethynyl linkers onto carbon fiber microelectrodes, paving the way for enhanced sensitivity and selectivity in copper sensing.”
Copper ions play a crucial role in various biological processes, including enzyme function and neural signaling. However, their dysregulation is linked to severe conditions like Alzheimer’s disease. Traditional methods for measuring copper involve complex and time-consuming procedures. The new sensors offer a simpler and more efficient alternative, maintaining high performance even in the presence of other interfering metal ions.
The team’s method involved a straightforward, single-step anodic deposition of DEB, which significantly increased the sensitivity and selectivity of the microelectrodes toward Cu(II). The researchers demonstrated that the multi-scan deposition of DEB resulted in a threefold increase in the sensitivity of the microelectrodes compared to unmodified electrodes. The modified sensors retained their enhanced performance over several days when stored at room temperature, marking a substantial improvement over existing technologies.
In an experimental setting, the researchers found that the multi-scan DEB-modified electrodes exhibited increased current density for Cu(II) reduction peaks, indicating higher sensitivity. Additionally, these sensors maintained their elevated sensitivity even when tested with solutions containing other divalent metal ions such as magnesium (Mg(II)), zinc (Zn(II)), and calcium (Ca(II)). This robustness against interference underscores the practicality of the new sensors for real-world applications.
Dr. Ou elaborated on the implications of their findings: “Our work demonstrates that these DEB-modified microelectrodes can serve as a versatile platform for detecting copper ions in various biological and environmental contexts. This could lead to better diagnostic tools and more precise monitoring of copper-related processes.”
The team’s comprehensive approach included evaluating the surface morphology of the modified electrodes using scanning electron microscopy (SEM). The images revealed that the multi-scan DEB deposition created an uneven surface with island-like structures, potentially contributing to the increased sensitivity by creating nucleation sites for Cu(II) deposition into Cu(0).
In conclusion, the development of these DEB-modified carbon fiber microelectrodes represents a significant advancement in electrochemical sensing technology. The enhanced sensitivity, selectivity, and stability of these sensors make them a promising tool for various applications, from medical diagnostics to environmental monitoring. The Dr. Ou’s team’s work opens new avenues for exploring and understanding copper dynamics in biological systems, potentially leading to breakthroughs in treating and managing copper-related disorders.
Journal Reference
Nudurupati, U., Narla, T., Punihaole, D., & Ou, Y. (2023). A facile approach to create sensitive and selective Cu(II) sensors on carbon fiber microelectrodes. RSC Advances, 13, 33688-33695. DOI: https://doi.org/10.1039/D3RA05119F
About the Authors
Yangguang Ou, Ph.D, is an assistant professor who joined the Department of Chemistry at UVM in Fall 2020. She is also a faculty member in the Neuroscience Graduate Program, the Cellular, Molecular, and Biomedical Sciences program, and the Vermont Center for Cardiovascular and Brain Health. Her research lies at the interface between bioanalytical chemistry and neuroscience. Her lab specializes in fast scan cyclic voltammetry at carbon fiber microelectrodes. Her long-term goal is to develop a versatile electrochemical sensing platform such that it is possible to detect any chemical biomarkers of interest. This will permit the expansion of personalized diagnostics devices for assessing mental health, nutrition, stress, or other neurochemical states of an individual in a quantitative manner.
David Punihaole, PhD is an Assistant of Chemistry at the University of Vermont and holds a graduate faculty appointment in the Materials Science program. He is also a Research Project Leader at the Vermont Center for Cardiovascular and Brain Health (VCCBH), an NIH-funded Center of Biomedical Research Excellence (COBRE). His research lies at the intersection of analytical and physical chemistry, as well as biophysics, materials science, and neuroscience. His research group is focused on developing chemical imaging tools that utilize Raman spectroscopy to directly visualize the molecular-level structural dynamics and non-covalent interactions of molecules in living cells. David’s group is interested in using this novel imaging technology to investigate protein folding regulatory mechanisms, understand the structural basis of amyloid fibril toxicity in neurodegenerative disorders such as Alzheimer’s Disease, and to establish structure-activity relationships of polymer- and lipid-based nanoparticle delivery vehicles used to transport drugs and therapeutic nucleic acids in gene/cancer therapies.
Uma is currently a 3rd year graduate student pursuing a PhD in analytical chemistry under the supervision of Dr. Yangguang Ou at the University of Vermont, USA. She has a Master of Science in Biophysics from UMass Amherst, USA, investigating structural proteins using light scattering, and she has a BS-MS in chemistry from the University of Hyderabad, India. She has twice received the prestigious Summer Research Fellowship from the Indian Academy of Sciences as an undergraduate student and has worked in fields spanning protein science, material science, spectroscopy, and electrochemistry. She has contributed to formulation development at RevBio LLC, Lowell, MA where her research laid the foundation for a new product line involving non-opioid pain-reliever-impregnated dental cement for post-operative care for wisdom tooth extraction. Outside the lab, she enjoys reading non-fiction books, listening to classical music, hiking, and fiber arts.
Terdha Narla is a recent graduate from the Department of Pharmacology’s Master’s program at the University of Vermont. She has a bachelor’s degree in pharmacy from India, where she worked on formulation and evaluation of tablets. Due to her interest in brain chemistry and associated disorders, she joined Dr. Yangguang Ou’s group where she worked for two years developing electrochemical tools that can be used to detect and monitor molecules of importance in neuronal signaling and gut-brain communication. While in the Ou lab, she co-authored two peer-reviewed publications, presented at regional and international conferences, and developed her writing skills. In addition to these research endeavors, Terdha has demonstrated a commitment to education and mentorship as a graduate teaching assistant, guiding undergraduate students in biology and neuroscience courses. Additionally, she has exhibited leadership by serving as the secretary and vice president of two graduate student-led clubs. Terdha is driven to learn new techniques and better understand brain physiology and neuropathogenesis. She aims to contribute to therapeutics and diagnostic tool development.
