By Rob Dyer

UVA ChemSciComm

These summaries describe a research project for five different levels of understanding, going from primary school to expert.

1. Primary School

            Our brains are very complex, but scientists at the University of Virginia under Prof. Venton are trying to understand how it works. They study the molecules that send signals throughout our brain that make it work. Their lab uses special instruments that measure the electrical signals that help these molecules work in our brains. The Venton Lab has discovered a new way to quickly and easily clean and prepare these instruments using a molecule called potassium hydroxide. This discovery provides a standard way to clean and reuse these devices that will enable researchers to more easily work to discover new things about our brains.

2. High School

            The human brain is a very complex organ with many different molecules that help it function. Researchers at the University of Virginia under Prof. Venton are working towards better understanding how it works. Their work focuses on studying neurotransmitters, the molecules that send signals throughout our brain, by using a technique that detects the electrical signals in the brain. Carbon fiber microelectrodes are devices that are used to carefully analyze these sensitive signals. The carbon fibers enhance the surface area and capabilities of these microelectrodes. Regular use of the devices will gradually reduce the sensitivity and degrade the device, but the Venton lab has discovered a new way to clean these devices to restore their original quality. By testing a variety of acidic, basic, and oxidizing solutions, they discovered that a treatment of potassium hydroxide, a strong base, can effectively clean and restore the electrodes. This discovery allows for an efficient means to clean and restore the electrodes after use and enhance the utility and lifespan of these instruments

3. College

            The human brain is a highly complex organ. Researchers at the University of Virginia under Prof. Venton are working towards better understanding how it works. Their work focuses on studying neurotransmitters by using a technique known as fast-scan cyclic voltammetry that detects the electric signals in the brain. Their lab uses carbon fiber microelectrodes to carefully analyze these sensitive signals. Regular use of the devices gradually reduces their sensitivity, but the Venton lab has discovered a new way to clean and treat these devices. By testing a variety of acidic, basic, and oxidizing solutions, they discovered that a treatment of potassium hydroxide can effectively clean and restore the electrodes. The treatment with KOH is 10 times faster than the other treatments at restoring the condition of the electrodes and even improves the sensitivity of the device. This discovery allows for an efficient means to clean and restore the electrode for use, even after use in biological systems.

4. Graduate Student in the Discipline

The human brain is a very complex organ. Researchers at the University of Virginia under Prof. Venton are working towards better understanding how it works. Their work focuses on studying neurotransmitters by using a technique known as fast-scan cyclic voltammetry that detects the electric signals in the brain. Carbon fiber microelectrodes (CFMEs) are the standard electrodes for fast-scan cyclic voltammetry (FSCV) detection of neurotransmitters. CFMEs are generally used untreated but the surface can be activated with different treatments to improve electrochemical performance. They used different solution conditions for electrochemical treatment and found that electrochemical pretreatment in KOH outperforms treatment in KCl, H₂O₂, or HCl by accelerating the surface renewal process. The etching rate of carbon with electrochemical treatment in KOH is 37 nm/min, which is 10 times faster than that in the other solutions. Electrochemical treatment in KOH for several minutes regenerates a new carbon surface, which introduces more oxygen functional groups beneficial for adsorption and electron transfer. The KOH-treated CFMEs improved the limit of detection (LOD) to 9 ± 2 nM from 14 ± 4 nM for untreated CFMEs, and they successfully detected stimulated dopamine release in rat brain slices, demonstrating that they are stable and sensitive enough to use in biological systems. Electrochemical treatment in KOH completely restores the electrode sensitivity after biofouling. The proposed electrochemical treatment is simple and fast and can be applied prior to using CFMEs or after use to restore the surface. Thus, the method has potential to be a standard step to clean the carbon surface, or restore the sensitivity of electrodes from biofouling.

5. Expert

Carbon fiber microelectrodes (CFMEs) are the standard electrodes for fast-scan cyclic voltammetry (FSCV) detection of neurotransmitters. CFMEs are generally used untreated but the surface can be activated with different treatments to improve electrochemical performance. In this work, we explored electrochemical treatments to clean and activate the CFME surface. The Venton Lab at the University of Virginia used different solution conditions for electrochemical treatment of used electrodes and found that electrochemical pretreatment in KOH outperforms treatment in KCl, H₂O₂, or HCl by accelerating the surface renewal process. The etching rate of carbon with electrochemical treatment in KOH is 37 nm/min, which is 10 times faster than that in the other solutions. Electrochemical treatment in KOH for several minutes regenerates a new carbon surface, which introduces more oxygen functional groups beneficial for adsorption and electron transfer. The KOH-treated CFMEs improved the limit of detection (LOD) to 9 ± 2 nM from 14 ± 4 nM for untreated CFMEs, and they successfully detected stimulated dopamine release in rat brain slices, demonstrating that they are stable and sensitive enough to use in biological systems. Electrochemical treatment in KOH completely restores the electrode sensitivity after biofouling. The proposed electrochemical treatment is simple and fast and can be applied prior to using CFMEs or after use to restore the surface. Thus, the method has potential to be a standard step to clean the carbon surface, or restore the sensitivity of electrodes from biofouling.