Gadolinium-doped carbon dots derived from peanut shell waste for bioimaging applications

Area of Science:

• Materials Science
• Nanotechnology
• Biomedical Engineering

Background:

• Food industry by-products represent a significant waste stream.
• Valorization of waste into functional nanomaterials is crucial for a circular economy.
• Carbon dots (CDs) are emerging nanomaterials with diverse biomedical applications.

Purpose of the Study:

• To synthesize and characterize Gadolinium-doped carbon dots (Gd-CDs) from peanut shell waste.
• To evaluate the potential of Gd-CDs as MRI contrast agents.
• To assess the biocompatibility of Gd-CDs for biomedical applications.

Main Methods:

• Synthesis of CDs from peanut shells followed by Gd-doping.
• Characterization using techniques like FTIR, DLS, and photoluminescence spectroscopy.
• Assessment of MRI contrast enhancement using 7 and 11.7 T scanners.
• Cytotoxicity assays on A549 cells.

Main Results:

• Gd-CDs were successfully synthesized, exhibiting sizes <20 nm and negative zeta potential.
• FTIR confirmed polar functional groups, ensuring excellent water dispersibility.
• Gd-doping enhanced UV absorption and showed fluorescence, though partially quenched at high concentrations.
• Gd-CDs demonstrated MRI contrast comparable to existing agents despite lower Gd content.
• Cytotoxicity assays confirmed biocompatibility up to 0.1 mg mL^-1.

Conclusions:

• This study presents a sustainable method for producing Gd-doped CDs from food waste.
• Gd-CDs show promise as biocompatible and effective MRI contrast agents.
• This approach supports waste valorization and the development of novel nanomaterials for medical imaging.