Fluorinated graphene oxide as a novel multimodal material for biological applications

R. Romero-Aburto
Rice University, US

Keywords: graphene, MRI, ultrasound, photoacoustics, hyperthermia

Summary:

Imaging contrast agents based on 19F are highly desirable due to the scarce distribution of fluorine in the human body and their ability to be detected by magnetic resonance imaging (MRI). We introduce a new multimodal material, fluorinated graphene oxide (FGO), where F is covalently bonded to the carbon (C) lattice of a graphene sheet. FGO is responsive to MRI, ultrasound (US), photoacoustics (PA) and hyperthermia induced by a near infrared (NIR) laser. FGO presents a typical paramagnetic curve when tested in a Superconducting Quantum Interference Device (SQUID). FGO MRI phantoms were compared with graphene oxide (GO) and relaxed water. Results indicated enhanced contrast in the spin-spin (T2) relaxation mode compared to GO and relaxed water. US demonstrated hyperechoic FGO as compared to the anechoic agar. The photoacoustic signal peaked at a wavelength of 720nm and as expected FGO and GO had the same trend. FGO selective heating under an 800nm NIR laser, translated into an increase in temperature from 20.1 to 62°C. Furthermore, in vitro studies on glioma cells confirm the ability of FGO as an inducible hyperthermic material when illuminated by a NIR laser. Our results introduce multimodal FGO to the biomaterials field.