Manganese oxide doped carbon dots for temperature-responsive biosensing and target bioimaging

Area of Science:

• Nanomaterials Science
• Biomedical Engineering
• Analytical Chemistry

Background:

• Carbon dots (CDs) are emerging fluorescent nanomaterials with excellent biocompatibility and tunable optical properties.
• Developing novel functional nanomaterials for bioimaging, sensing, and therapeutic applications is a key research area.

Purpose of the Study:

• To synthesize manganese oxide doped carbon dots (MnO_x-CDs) using a simple hydrothermal method.
• To investigate the potential of MnO_x-CDs for cellular imaging, temperature sensing, cancer cell migration inhibition, and selective detection of Fe³⁺ and biothiols.

Main Methods:

• Hydrothermal synthesis of MnO_x-CDs using manganese (III) acetylacetonate.
• Characterization of MnO_x-CDs' optical properties, including fluorescence and temperature sensitivity.
• In vitro evaluation of MnO_x-CDs for cellular imaging, cytotoxicity, cancer cell migration inhibition (scratch assay), and sensing of Fe³⁺ and biothiols.

Main Results:

• MnO_x-CDs were successfully synthesized, exhibiting water solubility, biocompatibility, low cytotoxicity, and blue fluorescence (Ex/Em: 326/442 nm, QY: 11.3%).
• Reversible temperature-sensitive fluorescence was observed in the range of 10-60 °C, enabling intracellular thermometry.
• MnO_x-CDs demonstrated inhibition of HepG2 cancer cell migration and acted as an "on-off-on" nanosensor for sequential detection of Fe³⁺ and biothiols in human serum.

Conclusions:

• MnO_x-CDs are promising candidates for liver cancer adjuvant therapy and advanced cellular imaging.
• The developed nanosensor offers a reliable and accurate method for detecting Fe³⁺ and biothiols in complex biological matrices.
• The findings highlight the versatility of MnO_x-CDs for diverse biomedical applications.