Robust Electrochemical Sensors for FSCV

Developing a sensor that helps to measure Hydrogen Peroxide levels for Fast Scan Cyclic Voltammetry (FSCV)

Sensor Waveform

Summary

Fast Scan Cyclic Voltammetry (FSCV) is a analytical chemistry technique that allows for real-time detection of electroactive species such as Dopamine and Hydrogen Peroxide ($H_2 O_2$). It does this by applying a triangular waveform to a carbon fiber electrode, then oxidizes and reduces species local to the position of the electrode, and finally computes the relative amounts of each when compared to the background amounts. Because of the speed at which this is done, and the voltages at which these species are oxidized, FSCV produces a unique chemical signature for many species like Dopamine. Unfortunately, many different species that are common within the brain produce a similar FSCV signature to $H_2 O_2$, a key marker in oxidative stress caused by neurodegenerative diseases such as Parkinson’s disease. We combated this problem by creating a new electrode; it is essentially a bare carbon fiber electrode and a carbon fiber electrode coated in mPD epoxied together. mPD essentially puts nanopore coating on the carbon fiber and only allows small molecules, like $H_2 O_2$ in. The figure above shows a cartoon what the looks like and what a physical one looks like with and without the coating under an electron microscope.

The talk discusses an application of this work. Parkinson’s Disease is one that strikes older people and is a neurodegenerative disease with an unclear cause. L-DOPA is the gold standard treatment for Parkinson’s Disease, but is a bit of an over-correction and causes abnormal rapid movements called dyskinesias. In this project, we were trying to understand the nature of these dyskinetic movements real-time, and did this using our mPD electrode in a Parkinson’s Disease mouse model. Through this project, we found an inverse correlation between dopamine and $H_2 O_2$ and between serotonin and $H_2 O_2$. In fact, fairly consistently, we observed a spike in dopamine before a dyskinetic movement, and a spike in $H_2 O_2$ during it.

This was the culmination of 2 years of work during my undergrad in the Sombers lab. I presented this work at a number of conferences, including Society for Neuroscience (SfN) and Pittconn, and even won an award for the best undergraduate poster and Triangle SfN. My capstone, which was a project I was working on for about a year, was awarded the most outstanding capstone as part of the University Honors Program.


๐Ÿ“š Hydrogen Peroxide, Dopamine, and Serotonin: Overlapping Chemical Systems Contribute to the Control of Dyskinetic Movements in the Rat During Chronic L-DOPA Treatment for Parkinsonโ€™s Disease

๐Ÿ† Won Richard L. Blanton Outstanding Capstone Award for talk

Sambit Panda, Leslie R. Wilson, Catherine F. Mason, Karen E. Butler, Christie A. Lee, Leslie A. Sombers

๐Ÿ“š Selective and Mechanically Robust Sensors for Electrochemical Measurements of Real-Time Hydrogen Peroxide Dynamics in Vivo

๐Ÿ† Won 1st Place and Travel Award for poster

Leslie R. Wilson, Sambit Panda, Andreas C. Schmidt, and Leslie A. Sombers

CiteใƒปPoster

Posted on:
May 20, 2018
Length:
3 minute read, 478 words
See Also: