A three-layered multifunctional photoactive core-shell gadolinium based nanocomposite

Multifunctional composite structures play an important role in biomedical applications, where many side effects can be eliminated and the therapy can be more effective. In this research, Gd ions and TiO2 were chosen to develop a potential material with image contrast enhancement behavior and photocatalytic properties. Such a unique combination would have the potential to be used as an efficient theranostic agent. Silica nanospheres were synthesized as a biocompatible platform through microemulsion method. The gadolinium carbonate layer was first formed around the silica cores, which can be transformed to Gd2O3 via calcination at 1000 °C. The outer TiO2 layer was deposited through controlled precipitation from TBOT as the precursor. The thickness of each layer was controlled by controlling the amount of its corresponding precursor. FESEM was used for morphological observations and the ultimate multilayer nanocomposite was confirmed using high resolution TEM. XRD and FTIR techniques were used to confirm the successful formation of each layer. The final nanocomposite particles with different layers thickness have an average diameter in the range of 47–76 nm. The nanocomposites were photoactive and able to decompose methylene blue by 45% after being exposed to UV radiation. The photocatalytic effect increased with TiO2 thickness and UV exposure time.