The authors describe MnO nanoparticles (NPs) with unique excitation-dependent fluorescence across the entire visible spectrum. These NPs are shown to be efficient optical nanoprobe for multicolor cellular imaging. Synthesis of the NPs is accomplished by a thermal decomposition method. The MnO NPs exhibit a high r1 relaxivity of 4.68 mM-1 s-1 and therefore give an enhanced contrast effect in magnetic resonance (MR) studies of brain glioma. The cytotoxicity assay, hemolysis analysis, and hematoxylin and eosin (H&E) staining tests verify that the MnO NPs are biocompatible. In the authors' perception, the simultaneous attributes of multicolor fluorescence and excellent MR functionality make this material a promising dual-modal nanoprobe for use in bio-imaging. Graphical abstract A direct method to synthesize fluorescent MnO NPs is reported. The NPs are biocompatible and have been successfully applied for multicolor cellular imaging and MR detection of brain glioma.
Keywords: Biocompatible; Brain tumor; C6 cells; Dual-modal nanoprobes; Mn-based nanoparticles; Optical imaging; T 1 contrast agents; Thermal decomposition; Tunable fluorescence; r 1 Relaxivity.