Name: Ledina Banushllari
Additional Authors:
Major/Area of Study/Graduate Department: Chemistry
Faculty Advisors: Silvana Andreescu
Dopamine is a catecholamine neurotransmitter that modulates and affects several aspects of brain activity and behavior. Detecting and measuring dopamine in a fast and efficient manner is necessary for controlling various diseases. To achieve this, extensive research has been conducted to develop accurate in vivo measurements of dopamine. Our research aims to replicate enzyme-mimetic-based carbon fiber microelectrodes, initially developed in the lab of Dr. Andreescu at Clarkson University. We propose replacing the enzyme with metal oxidase nanomaterials that exhibit similar behavior to polyphenol oxidase while improving sensitivity, detection limit, response time, oxidase-like activity, and minimizing interferences from other chemical neurotransmitters. To evaluate these factors, low holding potentials of -150 mV were applied (amperometry) over time.
Previously, microelectrodes consisted of carbon fibers, polyphenol oxidase, and metal oxide nanoparticles, all encapsulated in a biocompatible polymer. The enzyme (polyphenol oxidase) catalyzes the conversion of dopamine to o-dopaquinone, allowing reduction at a lower potential compared to without the enzyme. The mixture of metal oxides on the surface enhances the enzyme’s response to dopamine (low signals in the absence) and improves electrode stability. These microelectrodes exhibit low responsiveness to other chemicals due to the low reduction potential of the electrodes and the presence of tyrosinase. Furthermore, these microelectrodes are biocompatible and small enough to minimize tissue damage when implanted in vivo.
Replacing the enzyme with metal oxidase nanomaterials not only offers a cheaper and more readily available option but also improves stability against other chemicals. Additionally, by utilizing nanomaterials instead of enzymes, we can overcome the disadvantages associated with enzymes and provide an alternative fast scanning method for in vivo dopamine measurement.