Functionalized Carbon Dots from Bio-Based Precursors as Promising Fluorescent Probes for Cancer Cell Imaging.

Area of Science:

• Nanotechnology
• Biomedical Engineering
• Materials Science

Background:

• Carbon quantum dots (CQDs) are emerging nanomaterials with unique optical properties.
• Developing CQDs from natural precursors offers a sustainable and cost-effective approach.
• Surface modification is crucial for tuning CQD properties and enhancing their performance in biological applications.

Purpose of the Study:

• To synthesize and surface-modify CQDs from natural precursors using microwave-assisted methods.
• To evaluate the enhanced fluorescence properties of surface-engineered CQDs.
• To assess the biocompatibility and cellular uptake of CQDs for cancer cell visualization.

Main Methods:

• Microwave-assisted synthesis of CQDs using amino-glucose.
• Surface modification with betaine, marine collagen, or dopamine.
• Further functionalization with 7-amino-4-(trifluoromethyl)coumarin.
• Spectroscopic analysis (fluorescence emission), cytotoxicity assays (ISO 10993-5), and in vitro bioimaging.

Main Results:

• Successful synthesis and surface modification of CQDs confirmed by spectroscopy.
• Coumarin-modified CQDs exhibited enhanced fluorescence (~500 nm emission, 1.5-fold intensity increase).
• CQDs demonstrated excellent biocompatibility (cell viability >80% on MG-63 cells).
• Effective cellular uptake and bright intracellular staining observed in astrocytoma 1321N1 cells.

Conclusions:

• Surface-engineered CQDs derived from natural precursors show superior fluorescence and biocompatibility.
• These CQDs hold significant potential as biocompatible nanoprobes for cancer diagnostics.
• This work is a foundational step towards using CQDs for detecting circulating tumor cells (CTCs).