Bimodal Fluorescent and Magnetic Nanoparticles Based on Carbon Quantum Dots and Metal-Carbon Nanocomposites for Bio-Applications

The simultaneous combination of optical and magnetic properties of nanoparticles would greatly benefit in vivo disease diagnosis as well as in situ monitoring of cell in cell culture. The most promising application of magnetic particles in biomedicine is MRI contrast enhancement and magnetic hyperthermia. Another important thing is the determination of exact localization of nanoparticles in the cell culture that can be defined by e.g. optical way. In our investigation we used the iron nanoparticles encapsulated in carbon as a magnetic component and carbon quantum dots as an optical labels to provide the photostability and fluorescence in a wide range of wavelengths. In order to avoid the fluorescence quenching in bimodal particles the optical and magnetic components should be separated by insulator layer. To create the optimal bimodal nanoparticles for this purpose the non-typical configuration of nanocomposites was realized, namely, a fluorescent core was separated from the coated magnetic particles by silicon dioxide matrix. Finally, it was shown that these bimodal nanocomposites demonstrate the high magnetic properties, good visualized ability and low toxicity for living cells as well.