Primary School:
In the brain, there are neurotransmitters which send and receive signals based on what we see and do. To understand how the brain operates, we can study these neurotransmitters by measuring the electrical current they have as they are sending signals. Like an appliance in your house, our body uses electrical current to control and regulate itself. To measure the current which flows in neurotransmitters, we use conductive electrodes to measure changes in current. We want our electrodes to be very sensitive so they can measure the really small amounts of current that are produced by neurotransmitter signals sent in the brain. As a result, we make many kinds of electrode materials and test them to see which is the best for neurotransmitter detection.
High School:
In the brain, there are neurotransmitters which send and receive signals. There are certain neurotransmitters in the brain that are electroactive, which means they can be measured using an electrochemical technique. Studying these neurotransmitters can provide insight in neurodegenerative diseases, addiction, and mental health. Electrochemical measurements on a very short time scale are required to detect neurotransmitters, since neurochemical changes occur very rapidly in real time. To do this, we use carbon-based electrodes, which are conductive and can measure changes in current. We want our electrodes to have high sensitivity so they can measure the tiny neurotransmitter current signals sent in the brain. As a result, we make many kinds of electrodes and test them to see which is the best for neurotransmitter detection.
College:
There are certain neurotransmitters in the brain that are electroactive, which means they can be measured using an electrochemical technique. Studying these neurotransmitters can provide insight in neurodegenerative diseases, addiction, and mental health. Fast Scan Cyclic Voltammetry (FSCV) is a well-established technique used to detect neurotransmitters, as it has excellent experimental resolution with respect to time and can measure rapid neurochemical changes. Carbon Fiber Microelectrodes (CFMEs) are most commonly used as the working electrode in FSCV and are optimal for detecting monoamines such as dopamine and serotonin, which are part of the neurotransmitter signaling pathway. CFMEs are made up of a carbon fiber fused with a glass capillary tube, resulting in an electrode that is cylindrical and has a sharp tip that is ideal for inserting the electrode during studies with animal models. While CFMEs are sensitive for detecting dopamine and serotonin, they are not for secondary oxidation products and reduction products of neurotransmitters, which are produced during normal signalling. We develop novel carbon-based electrodes that have improved sensitivity compared to CFMEs. We recently developed Laser Induced Graphene from Parylene–N Microelectrodes (LIG-PNMEs), which has a 1.5x increased sensitivity for detecting dopamine and 1.3x increased sensitivity for serotonin compared to CFMEs.
Graduate Student in Discipline:
Fast Scan Cyclic Voltammetry (FSCV) is an electrochemical technique used for the detection of neurotransmitters. Carbon Fiber Microelectrodes (CFMEs) are most commonly used as the working electrode in FSCV and are optimal for detecting monoamines such as dopamine and serotonin. However, they have poor sensitivity for secondary oxidation products as well as reduction products of neurotransmitters. This is due to their smooth surface, which makes it easy for the analyte to desorb from the CFME back into solution. Electrodes that have a greater degree of surface roughness have been shown to have improved sensitivity relative to CFMEs. We recently developed Laser Induced Graphene from Parylene–N Microelectrodes (LIG-PNMEs), which had 1.5x increased sensitivity for detecting 1 µM dopamine and 1.3x increased sensitivity for serotonin compared to CFMEs. This signal enhancement is attributed to their increased surface roughness and defect sites, which can trap the analyte, in turn making it more difficult for it to desorb back into solution. Testing with other neurotransmitters, including, norepinephrine, epinephrine, ascorbic acid, and DOPAC on CFMEs and LIG-PNMEs is ongoing to determine which electrode has better performance across the all signaling mmolecules.
Expert:
Fast Scan Cyclic Voltammetry (FSCV) is an electrochemical technique used for the detection of neurotransmitters. Carbon Fiber Microelectrodes (CFMEs) are most commonly used as the working electrode in FSCV and are optimal for detecting monoamines such as dopamine and serotonin. However, they have poor sensitivity for secondary oxidation products as well as reduction products of neurotransmitters. This is due to their smooth surface, which makes it easy for the analyte to desorb from the CFME back into solution. Novel electrodes that exhibit more surface roughness are necessary have been shown to have improved sensitivity relative to CFMEs. We recently developed Laser Induced Graphene from Parylene–N Microelectrodes (LIG-PNMEs), which had 1.5x increased sensitivity for detecting 1 µM dopamine and 1.3x increased sensitivity for serotonin compared to CFMEs. This is attributed to their increased surface roughness and defect sites, which can trap the analyte, in turn making it more difficult for it to desorb back into solution. Interestingly, when used to detect 0.5 µM of adenosine, the LIG-PNMEs had reduced sensitivity than the CFMEs. This may be due to how much larger adenosine is than dopamine and serotonin, making it harder for it to be ‘trapped’ into small pockets on the surface of the electrode. On the other hand, it may be due to the sluggish electron transfer kinetics during the oxidation of adenosines. Testing with other neurotransmitters, including, norepinephrine, epinephrine, ascorbic acid, and DOPAC on CFMEs and LIG-PNMEs is ongoing to determine which electrode has better performance.