Date of Award
1-1-2025
Document Type
Thesis
Degree Name
M.S. in Pharmaceutical Science
First Advisor
Seongbong Jo
Second Advisor
Mohammed Maniruzzaman
Third Advisor
Michael Repka
School
University of Mississippi
Relational Format
dissertation/thesis
Abstract
In this study, carbon dots (CDs) were synthesized from agmatine sulfate, a bioactive molecule with nitrogen-rich moiety guanidine, and citric acid, a commonly used carbon source with oxygen-rich functional groups, at controlled temperatures of 180, 200, and 220°C, as well as CDs of agmatine only at 220°C using a hydrothermal method. The synthesized CDs were characterized for its optical properties, using UV–Vis, Fluorescence, chemical properties using, Fourier transform infrared (FT-IR) spectrophotometry, structural properties using Transmission electron microscopy (TEM) and for surface charge evaluation ζ-potential was measured. UV-Visible spectra confirmed CD formation through characteristic sp² hybridization bands. The synthesized CDs exhibited excitation dependent photoluminescence. TEM showed that 220-AgaCitCDs and 200-AgaCDs had particle sizes <10 nm. FTIR analysis indicated clearer functional group peaks with increasing temperature, especially in 220-AgaCitCDs and 220-AgaCDs, suggesting successful surface modification. ζ-potential measurements revealed pH dependence, with citric acid-based CDs showing more negative values than CDs generated solely from agmatine sulfate, especially at higher synthesis temperatures, indicating increased carboxylic and hydroxylic group presence. Cytotoxicity assays showed biocompatibility at concentrations ≤2.5 mg/mL for all CDs. Antimicrobial tests showed no significant activity against E. coli, likely due to the overall negative surface charge of CDs. It was noted through this study that the synthesis temperature and precursors had significantly influenced the physicochemical and biological properties of the carbon dots.
Recommended Citation
Chaudhari, Suyasha Sharad, "Synthesis and Characterization of Agmatine based Carbon dots" (2025). Electronic Theses and Dissertations. 3257.
https://egrove.olemiss.edu/etd/3257