Construction of Novel Fluorescent Carbon Dots with Excellent Antioxidant Properties: Surface Engineering Via Baicalein Modification and its Sensing Application

Abstract

The development of carbon dots (CDs) functionalized with antioxidant properties holds significant potential for biomedical and biosensing applications. In this study, we synthesized a novel fluorescent material, Ba/CDs, by functionalizing CDs with the flavonoid baicalein, enhancing their antioxidant capabilities. The morphology and structure of Ba/CDs were characterized using Transmission Electron Microscopy (TEM), X-Ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FT-IR), and X-ray Photoelectron Spectroscopy (XPS). The optical properties, water solubility, and antioxidant properties of Ba/CDs were investigated through Ultraviolet-Visible (UV-Vis) absorption and fluorescence spectroscopy. The antioxidant activity was assessed using DPPH free radical assay and H2O2 removal experiments, where Ba/CDs demonstrated significantly three fold higher antioxidant effectiveness than baicalein alone. Additionally, Ba/CDs served as a robust fluorescent probe for Fe3+ detection, showing a linear response over a concentration range of 0.1–60 μM with a detection limit of 84.3 nM. In actual sample tests, the Ba/CDs fluorescent probe achieved Fe3+ recovery rates of 97% to 102% in fetal bovine serum and water, with relative standard deviations (RSD) ranging from 2% to 4%. These findings highlight the potential of Ba/CDs as effective fluorescent probes for biological analysis in complex oxygen-containing environments.

Keywords: Fluorescent materials · Baicalein · Carbon dots · Antioxidant properties · Fe3+ detection