Assaying dopamine with saccharide carbon dots

Abstract

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Department of Chemistry College of Basic and Applied Sciences

Monday, November 20th, 2023 Science Building, Room 1191, 3:15 pm

Assaying dopamine with saccharide carbon dots

Peter Ogunsanya M.S Thesis Defense, CHEM 6800 Dr. Charles Chusuei, Chair Dr. Ngee Sing Chong Dr. Chengshan Wang

ABSTRACT Dopamine, also known as 4-(2-aminoethyl) benzene-1,2-diol (DA), is a neurotransmitter produced by brain neurons. It serves a crucial role in transmitting neurological signals. Dopamine exerts a substantial influence on various physiological systems in the human body, including the metabolism, central neurological system, renal system, and hormonal system.1 Insufficient levels of dopamine can lead to many neurological disorders, such as Parkinson's disease and schizophrenia, and a high level of dopamine excretion is a biomarker for the electrochemical detection of DA. This work explores the deposition of Saccharide carbon dots (namely lactose, glucose, and galactose) onto the surface of a glassy carbon electrode. This is followed by the deposition of a 2 wt% Nafion solution. The purpose of this process is to detect dopamine within two concentration ranges: 0.01mM – 0.1mM and 0.1mM – 1Mm. Cyclic voltammetry was employed to measure the relationship between current and concentration. At a concentration of 1mM, the lactose carbon dot exhibits the highest oxidation peak height, followed by glucose and then galactose. Studies on the selectivity between dopamine and the two other analytes—d-glucose and uric acid—that could obstruct neuroblastoma screening mechanisms during excretion were conducted. The results indicate that lactose CDs' reaction to GCE was largely selective for dopamine at the oxidation potential, with little to no response to either of the other analytes. The average size of the carbon dots, with a diameter of (156 ± 7) nm, was determined using scanning electron microscopy. This result provides an understanding of the uniformity of the carbon dots, with a diameter greater than the average size of carbon dots (>10nm), this also explains the discrepancy between the Raman results from Chusuei et al. and the behavior of carbon dots.2 REFERENCES (1) Zhang, Y.; Liu, F.; Xiao, F.; Wu, Q. Effects of an Ingredient of Bupleurum On Dopamine D2 Receptor-Mediated Signaling in Human Neuroblastoma Cell Line. Eur. Psychiatry 2015, 30, 1617. https://doi.org/10.1016/S0924-9338(15)31249-9. (2) Chusuei, C. C.; Clark, C. J.; Pandey, R. R.; Williams, E. T.; Shuxteau, C.; Seven, E. S.; Leblanc, R. M. Graphene Defects in Saccharide Carbon Dots Govern Electrochemical Sensitivity. Electroanalysis 2021, 33 (11), 2261–2266. https://doi.org/10.1002/elan.202100381.